CHEM210 / CHEM 210 Final Exam | Latest 2026–2027 Update | Organic Chemistry | Portage Learning | Verified Questions & Answers | Grade A

CHEM210 / CHEM 210 Final Exam | Latest 2026–2027 Update | Organic Chemistry | Portage Learning | Verified Questions & Answers | Grade A Q: What is ground state electron configuration of Co? [Ar]3d^9 [Ar]4s^1 3d^8 [Ar]4s^2 3d^7 [Ar]4s^2 4p^6 4d^1 Answer [Ar]4s^2 3d^7 Q: molybdenum has an anomalous electron configuration. using the shorthand notation for electron configurations, write the electron configuration A) [kr]5s 4d^6 B) [kr]5s 4d^0 5p^6 C) [kr]5s^1 4d^5 D) [kr]5s^2 4d^4 Answer C) [kr]5s^1 4d^5 Q: the symbol [Kr] represents a) 4s^2 4p^6 b) 1s^2 2s^2 2p^6 3s^6 4s^2 4p^6 c) 1s^2 2s^2 2p^6 3s^6 4s^2 3d^10 4p^6 D)1s^2 2s^2 2p^6 3s^6 4s^2 3d^10 4p^6 4d^10 Answer c) 1s^2 2s^2 2p^6 3s^6 4s^2 3d^10 4p^6 Q: What is the wavelength of UV light in the balmer series when m=2 and n=7? a) 0.00252 nm b) 397 nm c)337 nm d)0.00297 nm Answer b) 397 nm Q: How many electrons can a single orbital hold? A) 2n B) 2 C) 2l+1 D)8 Answer B) 2 Q: What are the possible values of I and m1 for an electron in a 5d orbitial? A) I=0 and mI=0 B) I=3 and MI=-2,-1,0,+1, or +2 c) I=1 and MI=-1,0,+1 D) I=2 and MI=-2,-1,0,+1, +2 Answer D) I=2 and MI=-2,-1,0,+1, +2 Q: What is the the de Broglie wavelength of an electron (m=9.11e-31 kg) moving at a velocity of 3.0e7m/s? a) 3.9e-12 b)2.4e-11 c)3.3e-8 d)1.1e-4 Answer b)2.4e-11 Q: What is the frequency of a helium-neon laser light with a wave of 632.8 nm? a) 4.47e14 s-1 b)4.47e5 s-1 c)2.11e-15 s-1 d)1.58e-15 s-1 Answer a) 4.47e14 s-1 Q: What is the correct nuclear symbol for the unknown product "X" in the nuclear equation shown below? A)234 TH 90 B) 226 Ra 88 C) 234 U 90 D) 242 Pu 94 E) 234 Pu 94 Answer A)234 TH 90 Q: The alpha particle is A)1 1 H B)2 1 H C)3 1 H D)4 2 He Answer D)4 2 He Q: An element has two naturally occurring isotopes. One has an abundance of 37.40% and an isotopic mass of 184.953 amu, and the other has an abundance of 62.60% and a mass of 186.956 amu. What is the atomic weight of the element? A) 185.7 amu B) 186.0 amu C) 186.2 amu D) 187.0 amu Answer C) 186.2 amu Q: What is the chemical symbol for an atom that has 29 protons and 36 neutrons? A) Cu B)Kr C)N D)Tb Answer A) Cu Q: How many protons (p) and neutrons (n) are in an atoms of 90Sr 38 A) 38 p, 52 n B) 38 p, 90 n C) 52 p, 38 n D) 90 p, 38 n Answer A) 38 p, 52 n Q: The observation that hydrogen and oxygen can react to form two compounds with different chemical and physical properties, one having an O:H mass ratio = 8:1 and the other having an O:H mass ratio = 16:1 is consistent with the law of A)definite proportions B) energy conservation C) mass conservation D)multiple proportions Answer multiple proportions Q: The observation that 15.0 g of hydrogen reacts with 120.0 g of oxygen to form 135.( g of water is evidence for the law of A) definite proportions. B) energy conservation. C) Mass conservation. D) multiple proportions. Answer Mass conservation Q: Argon belongs to the ____group A) alkali metal B)alkaline earth C)halogen D) noble gas Answer D) noble gas Q: Lithium belongs to the _____group of the periodic table: A) alkali metal B)alkaline earth C)halogen D) noble gas Answer A) alkali metal Q: To the correct number of sig figs, an automobile traveling at 28 mi/h is traveling at ___kn/h (1 km=0.6214 mi) A)17 b)17.40 C)45 D45.06 Answer 45 Q: how many sig figs are there in the following problem : 18.65+0.590=? A)one B)two C) three Answer D) four D) four Q: Which of the following has the greatest number of sig figs? A)0.5070 B)0.201 C)418 D)6.02e24 Answer A)0.05070 Q: A student measured the diameter of a sphere and determined the average value. His measurements are 5.17 cm, 5.16 cm, 5.16 cm, and 5.17 cm. If the true diameter is 6.18 cm, what can be said about the student's results? A) it is accurate and precise B)It is accurate but not precise C) it is precise but not accurate D) it is neither Answer C) it is precise but not accurate Q: If the melthing point of titanium metal is 16720C, what is its melting point in kelvin? A)897K B)1399K C)1945K D)3042 Answer C) 1945 K The diameter of an atom is approximately 1e-10m what is the diameter in millimeters? A)1e-16mm B)1e-13mm C)1e-7mm D)1e-4 mm Answer C) 1e-7 ,, convert 0.003002 to standard scientific notoation A)3.002e-3 B)3002e-6 C)3.0023 D3002e6 Answer A) 3.00e-3 A laboratory procedure requires 4.67 g of a liquid whose density is 1.034 g/mL. What volume of liquid should be used for this procedure? A) 4.83 mL B) 4.52 mL C) 0.221 mL D) 5.70 mL Answer B) 4.53 mL Which of the species below has 28 protons and 26 electrons? A)Fe^2+ B)Ni^2+ C) 54 26Fe D) 54 28Ni Answer B)Ni^2+ The definitive distinction between ionic bonding and covalent bonding is that A) ionic bonding involves a sharing of electrons and covalent bonding involves a transfer electrons. B) ionic bonding involves a transfer of electrons and covalent bonding involves a sharing electrons. C) ionic bonding requires two nonmetals and covalent bonding requires a metal and a nonmetal. D) covalent bonding requires two nonmetals and ionic bonding requires a metal and a nonmetal. Answer B) ionic bonding involves a transfer of electrons and covalent bonding involves a sharing electrons. What type of bonding is found in the compound PC15? A) covalent bonding B) hydrogen bonding C) ionic bonding D) metallic bonding Answer A) covalent bonding Which one of the following compounds contains ionic bonds? A) CaO B)HF C)NI3 D) Si02 Answer A) CaO Of the following, which element has the highest first ionization energy? A) Al B) Cl C) Na D) P Answer B) Cl Which is the most acceptable electron dot structure for N2H2? B) Which element can accommodate more then eight electron is its valance shell A) C B) O C) P D) He Answer C) P Which of the following contains an atom that does not obey the octect rule? A) KBr B) CO2 C)CIF3 D)ICI C) CIF3 consider a molecule with the following connections: when a vaild electron dot structure is written how many double bonds will the molecule contain? A) 0 B) 1 C) 2 D) 4 C) 2 How many resonanse structures are required in the electron-dot structure of CO3^2- A) two B) three C) four D) five B) three Assign formal cahared to each atom in the resonance form for SOCl2 given below A) 0 for cl, 0 for S, 0 for O B)0 for cl, +1 for S, -1 for O C) -1 for cl, +4 for S, -2 for O D) -1 for cl, -2 for S, -2 for O B)0 for cl, +1 for S, -1 for O the name for the compound formed from fluorine and bromine is A) bromine monofluoride B)fluorine monobromide C) monobromine momofluoride D) monofluorine monobromide A) bromine monofluoride What geometric arrangement of charge clouds is expected for an atom that has five charge clouds? A) tetrahedral B)square planar C) trigonal bipyramidal D) octahedral C) trigonal bipyramidal What is the molecular geometry of AsCl3 A) T-shaped B) tetrahedral C)trigonal planar D) trigonal pyramimidal D) trigonal pyramimidal Which orbital hybridization is associated with a tetrahedral charge cloud arragement? A) sp B) sp2 C) sp3 C) sp3 A triple bond is generally composed of A) three pi bonds B)two pi bonds and one ohmaga bond C) one pi bond and two ohmaga bond D) three ohmaga bonds B) two pi bonds and one ohmaga bond what is the molecular geometry of If5? A) octahedral B) seesaw C)square pyradmidal D) trigonal bipyramidal C)square pyradmidal What are bond angles in BCl3 A) 180 B) 109.5 C) 107 D) 120 D) 120 The MO diagram below is appropiate for B2 based on the diagram, B2 A) has a bond order of one and is diamagnetic B) has a bond order of one and is paramagnetic C) has a bond order of two and is diamagnetic D) has a bond order of two and is paramagnetic A) has a bond order of one and is diamagnetic Where are electron affinity values the highest? A) top left B) bottom left C) Top right D) Bottom right C) Top right Li2S is named A) lithium disulfide B) lithium sulfide C) lithium(II) sulfide D) lithium sulfur B) lithium sulfide What is the chemical formula for ferrous phosphate? A) Fe2P B) Fe2PO4 C)Fe3P2 D)Fe3(PO4)2 D)Fe3(PO4)2 Group 2A metals tend to be somewhat less reactive than alkali metals, and the order of their reacivity is A) BaSrCamgBe B)BeMgCaSrBa C) CaMgBeBaSr D) SrCaMgBeBa A) BaSrCamgBe which molecule contains the most polar bonds? A)CF4 B)CO2 C)CN D)CH4 A) CF4 The formula for dinitrogen trioxide is A) N(OH)3 B) (NO3)2 C) N2O3 D) N3O2 C) N2O3 What is the stoichiometric coefficient for oxygen when the following equation is balanced using the lowest, whole-number coefficients A) 3 B) 5 C) 7 D) 9 D) 9 . What is the mass of 0.500 mol of dichlorodifluoromethane, CF2CI2? A) 4.14e-3 B)60.5 g C) 121 g D) 242 g B) 60.5 g How many moles of CuO can be produced from 0.450 mol of Cu2O in the following reaction? A) 0.900 mol B) 0.450 mol C) 0.225 mol D) 1.80 mol A) 0.900 mol When 10.0 g of calcium metal is reacted with water, 5.00 g of calcium hydroxide is produced. Using the following balanced equation, calculate the percent yield for the reaction? A) 13.5% B) 27.1% C) 50.0% D) 92.4% B) 27.1% Which substance is the limiting reactant when 2.0 g of sulfur reacts with 3.0 g of oxygen and 4.0 g of sodium hydroxide according to the following chemical equation: 2 SO + 3 02(g) + 4 NaOH(aq) --9 2 Na2S04(aq) + 2 H20(1) A) S(s) B) O2(g) C) NaOH(aq) D) none of theses A) S What is the concentration of FeCI3 in a solution prepared by dissolving 10.0 g of FeCI3 in enough water to make 275 mL of solution? A) 0.224 M B) 2.224e-4 M C) 4.46 M D) 4.46e3 M A) 0.224 M Which of the following compounds contains the smallest percent oxygen by mass? A) CO2 B)N2O4 C)P4O10 D)SO2 D) SO2 Which one of the following is an empirical formula? A) C2F6 B)H2SO4 C) N2H4 D) P4O10 B) H2SO4 What term describes a solution of covalent-compound in water that does not conduct an electric current? A) amorphous solution B an electrolyte solution C) nonelectrolyte solution D) superconducting solution C) nonelectrolyte solution What is the solid product that forms when K2SO4(aq) and Pb(NO3)2(aq) are mixed? A) PbSO4 B) K2S03 C) Pb D) KN03 A) PbSO4 What is the chemical formula for sulfurous acid? A) H2S(aq) B) H2SO3 C) H2SO4 D) H2S2O7 B) H2SO3 12. What is the oxidation number of the chromium atom in K2Cr2O7? A) -2 B) +2 C) +6 D) +7 C) +6 What are the coefficients in front of NO3-(aq) and Cu(s) when the following redox equation is balance in an acidic solution A) 2,3 B)2,6 C)3,4 D)3,6 A) 2,3 What is the general term for the process in which a chemical species loses electrons? A) base B) Reduction C) dioxidation D) oxidation D) oxidation Which species functions as the reducing agent in the following reduction-oxidation reaction: ZnO+C----- Zn + CO A) C B) CO C) Zn D) ZnO A) C what ion is produced when arrhenius bases dissolve in water? A) H+ B) Na+ C) Cl- D) OH- D) OH- Which of the following is not a state function? A) altitude B)Heat C) internal energy D) volume Heat Calculate the work energy, w, gained or lost by the system when a gas expands from 15L to 35L against a constant external pressure of 1.5 atm.{1L*atm=101J} A) -5.3kJ B)+3.0kJ C) -3.0kJ D) +5.3 C) -3.0 kJ A reaction is carried out at constant pressure; q=125kJ and w=-15kJ. what are values of ^V and ^H a) E=110kJ and H=125kJ B)E=125kJ and H=110kJ C) E=125kJ and H-140kJ D) E=140 and H=125kJ A) 110kJ and 125 Which of the following statements does not represent an exothermic reaction? A) Heat is transferred from system to surroundings B) Heat is transferred from surroundings to system ) C) Feels hot D) Energy is represented as a product B) heat is transferred from surrounding to system The enthalpy of fusion, or heat of fusion (^Hfusion) of water is positive and corresponds to which physical change? A) H20(g) - H20(s) B) H20(1) -- H20(s) C) H20(s) - H20(1) D) H20(s) - H20(g) C) H20(S)----H20(I) The specific heat of copper is 0.385 J/(g • 0C). If 34.2 g of copper, initially at 250C absorbs 4.689 kJ, what will the final temperature of the copper be? (Hint: check your units) A)25.4 C B)27.8 C C) 356 C D) 381 C C) 356 C use the given standard enthalpies of formation to calculate ^Hrxn for the following 3 Fe2O3(s) + CO(g) - 2 Fe3O4(s) + CO2(g) A) -5213.4 kJ B)-577.2 kJ C) -47.2 D) +47.2kJ C) -47.2 kJ One method for making ethanol, C2H50H, involves the gas-phase hydration of ethylene, C2H4. Estimate AH for this reaction from the given average bond dissociation energies, D A) -35 kJ B)-580 kJ C) +35 kJ D) 580 kJ A) -35 kJ Which of the following can be interpreted as a measure of randomness? A) enthalpy B) entropy C) free energy D) temperature B) entropy T/F nitrogen is called the superglue of the chemical world false T/F large elements, such as strontium, are common in biomolecules false T/F the time it takes for a compound to flow through a metabolic pathway is called the payoff phase false T/F proteins, carbohydrates, and fats all get broken down into acetyl-CoA true T/F a fat is a lipid molecule that is a solid at room temperature true in DNA, guanine always pairs with ____ A. thymine B. guanine C. uracil D. cytosine E. both A and B D. cytosine water is considered a polar solvent due to attractive forces known as hydrogen bonds. a hydrogen bond is _____ A. a bond that is stronger than a covalent bond B. an attractive force between molecules where partially positive hydrogen atoms are attracted to partially negative atoms of F, O, or N C. the polar O-H bond in water D. an ionic bond between H and another atom E. a covalent bond between H and O B. an attractive force between molecules where partially positive hydrogen atoms are attracted to partially negative atoms of F, O, or N what is a unique molecule. which of the following contributes to water's unique place in the chemical world? A. the geometry of the molecule B. the polarity of the O-H bonds C. the ability of water molecules to hydrogen bond D. the bond angle of water E. all of the answers are correct E. all of the answers are correct the H+ concentration of a solution is 7.9x10^-13M. what is the pH? A. -6.70 B. 6.70 C. 11.17 D. -12.1 E. 12.1 E. 12.1 which of the following is the enthalpy change of a reaction? A. delta G B. delta S C. delta H D. delta F E. none of the above C. delta H a globular protein is an example of a protein _____ A. motif B. conformation C. secondary structure D. quaternary structure E. amino acid B. conformation any molecule or ion that is necessary for an enzyme's function is called a ____ A. cofactor B. coreactant C. coproduct D. bienzyme E. both B and C A. cofactor a(n) ____ is a compound that binds to an enzyme in such a way that the enzyme slows down or stop the enzyme reactions. A. ligand B. substrate C. inhibitor D. coenzyme E. deactivator C. inhibitor the following are all examples of a carbohydrate's function in cells except____ A. structural role in RNA B. structural role in DNA C. intermediate in metabolism D. basis for building proteins E. energy source for cells D. basis for building proteins a particular lipid is a liquid at room temperature, so it is called a(n)___ A. oil B. fat C. lipid D. membrane E. sphingolipid A. oil the following separates life from non-life A. cellular membranes B. carbohydrates that provide the necessary energy C. fats that provide energy to organisms D. protein transporting oxygen E. none of the above A. cellular membranes the primary sequence of proteins is written _____ A. N to C B. C to N C. 5' to 3' D. 3' to 5' E. both A and D A. N to C A lipid is______ A. a fat B. an oil C. a molecule that dissolves in a non-polar solvent D. is made from isoprene units E. is water soluble C. a molecule that dissolves in a non-polar solvent lipids are catabolized by the _____ pathway A. glycolysis B. beta-oxidation C. urea cycle D. both A and C E. both B and C B. beta-oxidation FADH2 provides energy by donating electrons and hydrogens to the _____ A. ETC B. CAC C. beta-oxidation pathway D. glycolysis pathwat E. all of the above A. ETC the direct production of ATP occurs as H+ ions flow through ______ into the mitochondrial matrix A. complex I B. complex II C. complex III D. complex IV E. ATP synthase E. ATP synthase T/F hydrogen is called the superglue of the chemical worlds false T/F small elements such as nitrogen, are common in biomolecules true T/F the time it takes for a compound to flow through a metabolic pathway is called the flux true T/F carbohydrates and fats all get broken down into NADH and FADH2 in energy production true T/F a fat is a lipid molecule that is liquid at room temperature false In RNA, guanine always pairs with ________. A. thymine B. guanine C. cytosine D. uracil E. both A and B C. cytosine water is considered a polar solvent due to attractive forces known as hydrogen bonds. a hydrogen bond is _______ A. a covalent bond between H and O B. the polar O-H bond in water where the dipoles arrows are pointed toward the hydrogen atom C. an ionic bond between H and another atom D. an interaction on different molecules where partially negative atoms of F, O, or N interact with partially positive hydrogen atoms E. a bond that is stronger than a covalent bond D. an interaction on different molecules where partially negative atoms of F, O, or N interact with partially positive hydrogen atoms which attribute contributes to water's unusual properties? A. the geometry or the molecule B. the polarity of the O-H bonds C. the ability of water molecules to hydrogen bond D. the bond angle of water E. all of the answers are correct E. all of the answers are correct the H+ concentration of a solution is 6.3x10^-2M. what is the pH? A. -1.20 B. 1.20 C. 3.12 D. -2.92 E. 2.92 B. 1.20 a fibrous protein is an example of a protein _______ A. quaternary structure B. motif C. secondary structure D. amino acid E. conformation E. conformation an organic molecule that is necessary for an enzymes function is called a___ A. cofactor B. coreactant C. coenzyme D. bienzyme E. both B and C C. coenzyme the following are all examples of a protein's functioning in cells except______ A. building block for cellulose B. catalysis (enzymes) C. transport of molecules D. structure of ribosomes E. communication (hormones) A. building block for cellulose a particular lipid is a solid at room temperature, so it is called a(n)_____ A. carotenoid B. oil C. sphingolipid D. fat E. membrane D. fat carbohydrates are catabolized by the _____ pathway A. glycolysis B. beta-oxidation C. urea cycle D. both A and C E. both B and C A. glycolysis which of the following is the free-energy change of a reaction? A. delta G B. delta S C. delta H D. delta F E. none of the above A. delta G proteins are catabolized by the ____ pathway A. glycolysis B. beta-oxidation C. urea cycle D. both A and C E. both B and C C. urea cycle in a particular cell, molecule X binds to an enzyme causing it to stop catalyzing reactions. molecule X is called what? A. ligand B. substrate C. coenzyme D. deactivator E. inhibitor E. inhibitor the following are all examples of a lipid's function in cells except_____ A. energy source B. structural role in membranes C. structural role in myelin sheaths D. the basis for dye molecules (carotenoids) E. catalysis E. catalysis the following separated life from non-life A. enzymes that catalyze metabolic reactions B. carbohydrates that provide the necessary structure C. fats that provide energy to organisms D. lipid bilayer surrounding the cell E. none of the above D. lipid bilayer surrounding the cell In particular gravimetric analysis, the precipitate of bariums ulfate was weighed before it was completely dried. The likely impact of this error on the calculated result is. A. Minimal, because the mass of water is very low. B. Lower result than correct value. C. Higher result than correct value. D. Minimal, because calculation assumes a hydrated sample is produced. E. All of the above are not correct. C. Higher result than correct value. Atomic spectroscopy is... A. Measurement of intensity of emitted light at a particular wavelength from the atoms that are excited thermally. B. Measurement of absorbance of emitted light at particular wavelength from atoms excited thermally. C. Measurement of intensity of emitted light at particular wavelength from the atoms that are excited by monochromatic light. D. Measurement of intensity of absorbed light at a particular wavelength from the atoms that are excited thermally. E. None of the above. A. Measurement of intensity of emitted light at a particular wavelength from the atoms that are excited thermally. In many countries, fish with more than 0.500 ppm mercury is considered unsafe. In one experiment, a 0.750 g piece of tuna was appropriately treated and made up to 10.0 mL solution. This solution returned an absorbance of 0.70. Using the calibration graph below, what can be concluded from this analysis? A. The tuna does not contain mercury. B. The concentration of mercury in the tuna is less than 0.500 ppm and it can be eaten safely. C. The concentration of mercury is exactly equal to 0.500 ppm and may or may not be safe to eat. D. The concentration of mercury in the tuna is greater than 0.500 ppm and it should not be eaten. E. None of the above. D. The concentration of mercury in the tuna is greater than 0.500 ppm and it should not be eaten. Of the following compounds, which would you expect to elute first from a nonpolar gas chromatographic column? A. Methanol (CH3OH) B. Ethanol (CH3CH2OH) C. n-Propanol (CH3CH2CH2OH) D. n-Butanol (CH3CH2CH2CH2OH) E. n-Pentanol (CH3CH2CH2CH2CH2OH) A. Methanol (CH3OH) Separation of ions in mass spectrometer take place on the basis of which of the following? A) Mass B) Charge C) Molecular weight D) Mass to charge ratio E) None of the above. D) Mass to charge ratio Which of the following are examples of systematic errors? I. Weighing a precipitate on an electronic balance. II. Consistently reading burette volumes from the top of the meniscus. III. Using an incorrectly labelled standard solution in a titration. A. I, II and III B. I and III only C. I and II only D. II and III only E. III only D. II and III only What is the molar concentration and absolute uncertainty of a solution made by dissolving 1.065 ± 0.001 g of Na2CO3 in 50.0 ± 0.3 mL of distilled water? A. 0.201± 0.050 mol/L B. 0.201± 0.001 mol/L C. 0.201± 0.301 mol/L D. 0.201± 0.694 mol/L E. None of these B. 0.201± 0.001 mol/L When using an internal standard, the identity of the standard is : A. Different than the analyte and of known concentrations. B. The same as the analyte and at the same concentration. C. It could be the same or different relative to the analyte. D. It should be the same as the analyte but of different (known) concentrations. E. All above are not correct. A. Different than the analyte and of known concentrations. The weight percent concentration of an aqueous phosphoric acid is 28%; this means that (assuming the density of the solution is 1 g/mL): A. 1 L of this solution contains 28 mL of phosphoric acid B. 100 mL of this solution contains 28 g of phosphoric acid C. 1 mL of this solution contains 28 g of phosphoric acid D. 28 g of phosphoric acid dissolved in 100 mL of water E. 1 L of this solution has a mass of 28 g of phosphoric acid B. 100 mL of this solution contains 28 g of phosphoric acid A 0.1500 M HCl solution was prepared on a day when the temperature was 20 C. What is concentration of the solution when used the next day at 27 C? The density of water is 0.9982071 g/mL at 20 C and 0.9965162 g/mL at 27 C. A. 0.1508 M B. 6.632 M C. 0.1503 M D. 6.653 M E. 0.1497 M E. 0.1497 M For a specific reaction, which of the following statements can be made about K, the equilibrium constant? A.It always remains the same at different reaction conditions (concentrations and temperature). B. It increases if the concentration of one of the products is increased. C. It changes with changes in the temperature. D.It increases if the concentration of one of the reactants is increased. E. It may be changed by the addition of a catalyst. C. It changes with changes in the temperature. What is the molar solubility, s, of Ba3(PO4)2 in terms of Ksp? A. s = Ksp 1/2 B. s = Ksp 1/5 C. s = (Ksp/27)1/5 D. s = (Ksp/108)1/5 E. s = (Ksp/4)5 D. s = (Ksp/108)1/5 As pure water is heated, its pH decreases. This means that: A. the water is now acidic B. [H+] [OH-] C. [OH-] [H+] D. [H+] = [OH-] E. Both a) and b) are correct D. [H+] = [OH-] The ionic strength of a 0.012 M solution of the soluble weak acid CH3COOH (Ka = 1.75 x 10-5) is: A. 0.024 M B. 0.012 M C. 0.036 M D. 0.012 M E. Cannot be determined D. 0.012 M As the ionic strength decreases, the value of activity coefficient approaches: A. 1.0 B. 0.1 C. 7.0 D. 14.0 E. There is no specific value A. 1.0 If water were added to a 0.25M C2H5NH2 solution (Kb = 4.3 10-4), the amount of OH (number of moles) would _____ and the OH concentration would _____. A. Increase, increase B. Increase, decrease C. No change, no change D. Decrease, decrease E. Decrease, increase B. Increase, decrease Which of the following combinations cannot produce a buffer solution? A. HNO2 and NaNO2 B. HCN and NaCN C. HClO4 and NaClO4 D. NH3 and (NH4)2SO4 E. NH3 and NH4Br C. HClO4 and NaClO4 What is the main difference between monoprotic and polyprotic acids? A. Monoprotic acids produce one proton, polyprotic contain many. B. Monoprotic acids dissociation 100% in solution, polyprotic acids do not. C. Monoprotic acids are strong acids, polyprotic acids are weak. D. Monoprotic acids have lower Ka values than polyprotic acids. E. None of the above. A. Monoprotic acids produce one proton, polyprotic contain many. Ammonia (NH3) is a well-known weak base for which the conjugate acid is ammonium (NH4 +). Which of the following would be the titration reaction for ammonia (with a strong acid)? A. NH4 + NH3 + H+ B. NH4 + + H2O NH3 + OH C. NH4 + + H2O NH3 + H3O+ D. NH3 + H2O NH4 + + OH E. NH3 + H3O+ NH4 + + H2O E. NH3 + H3O+ NH4 + + H2O The following titration curve is the kind of curve expected for the titration of a ____ acid with a ____ base. A. Strong, strong B. Weak, strong C. Strong, weak D. Weak, weak E. None of these A. Strong, strong Ammonia (NH3) is a well-known weak base for which the conjugate acid is ammonium (NH4 +). Which of the following would be the hydrolysis reaction for ammonia, i.e., the reaction for which the equilibrium constant is its Kb. A. NH4 + NH3 + H+ B. NH4 + + H2O NH3H2O + H+ C. NH4 + + H2O NH3 + H3O+ D. NH3 + H2O NH4 + + OH E. None of these is correct. D. NH3 + H2O NH4 + + OH Which of the following is an example of a polyprotic acid? A. H2CO3 B. HNO3 C. HI D. HCl E. CH3COOH A. H2CO3 Which of the following would cause a sharper change at the equivalent point of an EDTA titration? A. Increasing the concentration of the analyte B. Decreasing the concentration of the analyte C. Decreasing the concentration of the EDTA solution D. Increasing the concentration of the EDTA solution E. Increasing the conditional formation constant (K'f ) of the [metal-EDTA] complex E. Increasing the conditional formation constant (K'f ) of the [metal-EDTA] complex Which of the following is a redox reaction? A. 2Na + 2H2O 2NaOH + H2 B. CaCO3 CaO + CO2 C. AgNO3 + NaCl AgCl + NaNO3 D. CaCO3 +2HCl CaCl2 + H2O+ CO2 E. Ca2+ + Y4- CaY2- A. 2Na + 2H2O 2NaOH + H2 The cell potential, E°, for a redox reaction was found to equal +1.10 V. What can be said about this reaction? A. Equilibrium B. Endothermic C. Nonspontaneous D. Spontaneous E. None of above D. Spontaneous Given the equation: 2Cr(s) + 3Pb2+(aq) 2Cr3+(aq) + 3Pb(s), which is the correct half reaction occurring on the cathode? A. Cr(s) Cr3+(aq) + 3e B. Pb2+(aq) Pb(s) + 2e C. Cr(s) + 3e- Cr3+(aq) D.Pb2+(aq) + 2e- Pb(s) E. None of these D.Pb2+(aq) + 2e- Pb(s) A pH meter is an example of: A. Reference electrode. B. Electrolytic cell C. Fuel cell. D) Ion-selective electrode E) Glass tube. D) Ion-selective electrode Select the incorrect statement from the following: constant temperature is important in potentiometry measurements using ion-selective electrodes because... A. These electrodes don't work if not used at room temperature. B. The potential readings change with temperature C. The slope of the calibration graph is temperature dependent D. It takes electrodes longer time to reach thermal equilibrium at low temperature E. The performance of these electrodes is not influenced by the temperature, as long as it is constant A. These electrodes don't work if not used at room temperature. Dilute sulfuric acid is electrolyzed using inert electrodes. A. 2 moles of O2 at the anode, 1 mole of H2 at the cathode B. 2 moles of H2 at the anode, 1 mole of O2 at the cathode C. 1 mole of H2 at the anode, 2 moles of O2 at the cathode D. 1 mole of O2 at the anode, 2 moles of H2 at the cathode E. All above are not correct D. 1 mole of O2 at the anode, 2 moles of H2 at the cathode All of the following are the advantages of dropping mercury electrode, except... A. Constant renewal of electrode surface which eliminates poisoning and contamination B. Mercury forms amalgams with many metals and thus decreases their reduction potentials C. Useful for detection of many ionic species less than 0.001 M D. Diffusion current can be readily adapted for constructing a calibration curve for an analyte of interest E. Has wide potential range in the positive direction vs. SHE The following reaction occurs in a basic solution. Identify the oxidizing agent. Note the reaction equation is not balanced. H2O(l) + Zn(s) + NO3 -(aq) + OH-(aq) →Zn(OH)4 2-(aq) + NH3(aq) A. Zn(s) B. H2O(l) (the oxygen) C. NO3 -(aq) (the nitrogen) D. NH3(aq) (the nitrogen) E. OH-(aq) C. NO3 -(aq) (the nitrogen) Which instrument is used to detect the end point of a redox titration? A. Potentiometer B. Conductometer C. Potentiostat D. Any one of the above E. None of the above A. Potentiometer The peak current in a cyclic voltammogram is related to: A. The standard electrode reduction potential for the redox couple under investigation B. The potential of the reference electrode C. The concentration of the redox couple under investigation D. The standard reduction potential of water E. None of the above Sputtering Specific term used to describe creation of an atomic cloud when high energy gaseous cations impact the cathode surface in a hollow cathode lamp. Flame AAS Bernoulli effect is used in this ANALYSIS TECHNIQUE (choose either Flame AAS or Electrothermal AAS) for sample introduction. Interzonal area Stable part of a flame which is rich in atoms. Graphite furnace Used for sample atomization in an electrothermal AAS. Aspiration Process by which a solution is sucked into a flame in AAS. Aerosol A mist of fine droplets. Flashback Flame propagation into the burner. TRUE OR FALSE GC carrier gases are generally inert gases like helium and nitrogen. TRUE TRUE OR FALSE A TCD is insensitive to non-combustible gases such as water and carbon dioxide. FALSE TRUE OR FALSE The injection port temperature should be set at the average boiling point of all analytes. FALSE TRUE OR FALSE A column temperature equal to or slightly above the average boiling point of the sample components results in a reasonable elution time. TRUE TRUE OR FALSE An FID is insensitive to non-combustible gases such as water and carbon dioxide. TRUE Hard ionization General term used to describe ionization techniques that produces many ion fragments. Electron ionization is an example of this. Molecular ion peak Feature in a mass spectrum that is due to a singly charged ion that has the same mass as the analyte. Matrix-Assisted Laser Desorption/Ionization (MALDI) This ionization technique is used to analyze large, non-volatile molecules. Ions are formed by placing the analyte in an excess of UV-absorbing molecules, followed by irradiation with a laser. Electrospray ionization (ESI) This ionization technique is used to analyze large, non-volatile molecules. Ions are formed by injecting the sample solution across a high potential difference producing multiply protonated molecules whose charge tends to increase with the size of the molecule. Soft ionization General term used to describe ionization techniques that produces few ion fragments. Chemical ionization is an example of this. Base peak The most abundant fragment results in this mass spectrum feature. Fast atomic bombardment (FAB) This ionization technique is used to analyze large, non-volatile molecules. The analyte is dissolved in a liquid matrix and placed on a target where it is impacted with an atom beam. Ion trap Storage of ions in space defined by ring and end cap electrodes. Electric field sequentially ejects ions of increasing m/z values. Quadrupole This is the most widely used mass analyzer. It is composed of four precisely machined, parallel, conductive rods. A DC current and RF field is applied, which helps separate particles by affecting their path stability from injection to detection. Ions that are affected by the DC and RF field collide into the poles and are not detected (non-resonant ions), while those which are not as affected continue to the detector (resonant ions). By manipulating the voltages of both the DC and RF field, we can scan for different ions. Primary combustion zone Blue luminescence from band spectra of C2, CH, & other radicals ( no thermal equilibrium) Anode The electrode at which oxidation occurs, reducing electrode, negative Electrothermal AAS Atomization Reduction to small particles Cathode The electrode at which reduction occurs, oxidizing electrode, positive Nebulization Process of making a fine mist; a method of drug administration (asthma inhaler) Plazma Matter that exists as ions and give off light; the most abundant state in the universe Magnetic sector A device that separates gaseous ions that have the same kinetic energy by passing them through a magnetic field perpendicular to their velocity. Trajectories of ions with a certain mass-to-charge ratio are bent exactly enough to reach the detector. Other ions are deflected too much or too little. Why is it not ideal to have quantitative precipitation? Insoluble Filterable Ultrapure Co-precipitation Occurs when there are adsorbed or absorbed (included or occluded) impurities Absorbed impurites Present within the bulk of the precipitate Inclusion Impurities occupy the crystal lattice sites. Occlusion Impurities (other ions or precipitates) are trapped inside the growing crystal Re-precipitation Procedure including washing away the mother liquor, redissolving the precipitate and precipitating the product again Peptization Break up of the precipitate (AgCl) because of a loss of electrolyte (HNO3) if the precipitate is washed by water Gravimetric combustion analysis To determine the carbon and hydrogen content of organic compounds burned in excess O2 Elemental analysis To determine the C, H, N, and S contents in a single operation by using modern instruments such GC and thermal conductivity measurements Atomic absorption After absorption of photons, the electrons are excited from their ground states into excited states Atomic emission After excitation (thermal or plasma) of electrons, they relax back to their ground states, and photons are emitted. Atomic fluorescence After excitation (by laser) of electrons, they relax and photons are emitted Hollow-cathode lamp (HCL) Light source or radiation source to excite electrons of a metal of interest to a higher energy level. Flame Pre-mix flame in which fuel (acetylene) and oxidant (air) and sample are first mixed and then burnt Oxidant/fuel ratio Excess oxidant leads to a lean flame, which produces a hotter flame to atomize refractory (high boiling) compounds Excess fuel leads to a rich flame, which causes reduction of oxides and hydroxides and increases sensitivity Spectra interferences Unwanted signals (due to the flame or due to other elements or molecules in the sample) overlap with the analyte signal Solutions: choose another wavelength for analysis Chemical interferences Chemical reaction decreases the concentration of the analyte atoms, e.g., sulfate or phosphate hinder the atomization of Ca. Solutions: : EDTA can be added to protect Ca2+ from reacting with the interferences. La3+ can also be added to release Ca by preferentially reacts with phosphate Ionization interferences Ionization of analyte atoms decrease their concentration Solutions: Addition of e- by an ionization suppressor (or a more easily ionized element such as Cs) can increase the concentration of the neutral atoms Chromatography Addition of e- by an ionization suppressor (or a more easily ionized element such as Cs) can increase the concentration of the neutral atoms Steps in analytical process 1. Formulating question 2. Selecting analytical procedures 3. Sampling 4 - 6. Sample preparation 7. Analysis 8. Report 9. Drawing conclusions Method of least squares Process of fitting a mathematical function to a set of measured points by minimizing the sum of the squares of the distances from the points to the curve Calibration curves Shows the response of an analytical method to known quantities of analyte Steps in making a calibration curve... 1. Prepare standards covering a reasonable range 2. Measuring the signals of standard solutions. 3. Make graph, find the best straight line using the least-squares method and derive the equation. 4. Measuring the signal of the unknown solution. 5. Use the equation to solve for the unknown concentration. Standard addition 1. Add known quantities of analyte to the unknown. 2. Deduce the amount of initial analyte form the increase of the signal. 3. A linear response is required Internal standard -Add a known amount of a compound, different from the analyte to the unknown. -The signal from the internal standard is compared with that from analyte to find out how much analyte is present. Molarity Moles of solute / volume of solution (L) Molality Moles of solute / weight of solvent (kg) Solubility product The equilibrium constant for the reaction in which a solid salt dissolves, to give its constituent ions in solutions. Le Chatelier's Principle The direction the system re-establish equilibrium after a change is in such a way that the change is partially offset. Selective precipitation -Precipitation reactions can sometimes be used to separate ions from each other based on the differences in their solubility products. -If the stoichiometries are the same, the smaller Ksp implies a lower solubility. Ionic strength and activity The greater the ionic strength (measure of total ionic charges in solution) of a solution, the higher the charge in the ionic atmosphere. Each ion-plus-atmosphere contains less net charge, so there is less attraction between any particular cation and anion. Charge balance Electroneutrality of the solution: the sum of the positive charge in solution equals the sum of negative charges in the solution. Mass balance Conservation of matter: the quantity of all species in a solution containing a particular atom (or group of atoms) must equal to the amount of that atom (or group) delivered to the solution. Buffer Mixture of a weak acid and its conjugate base Buffer capacity Measure of how well a solution resists changes in pH when strong acid or base added Reduction Gain of electrons Oxidation Loss of electrons Voltage vs. free energy Free energy change of a chemical reaction is related to the potential difference (i.e., the voltage) that can be generated by the reaction Galvanic cells An electrochemical cell in which a spontaneous reaction generates a flow of current. Salt bridge Connecting the two half-cells but separate the reactants. Standard potential The potential difference, E°, between the standard potential of the reaction of interest and the potential of the standard hydrogen electrode (SHE), which is arbitrary set to zero. Nernst equation steps (for a complete cell): 1. Write reduction half-reactions for both half-cells and find Eo, multiply the half reaction as necessary. 2. Write a Nernst equation for the cathode (positive terminal), EC. 3. Write a Nernst equation for the anode (negative terminal), EA. 4. Find the net cell voltage by subtraction: E = EC - ER 5. Write a balanced net cell reaction, subtract the anode half reaction from the cathode half-reaction. Formal potential E°', is the reduction potential that applies under a specified set of conditions: pH, ionic strength, and concentrations of complexing agents. Working electrodes - Metal electrodes - Ion-selective electrodes Metal electrodes Develop an electric potential in response to a redox reaction at the metal surfaces. Ion-selective electrodes Selective migration of one type of ion across the electrode membrane generates an electric potential. Junction potential - Developed when two dissimilar electrolyte solutions are in contact - Its presence puts a fundamental limitation on the accuracy of direct potentiometric measurements. Principles of Ion-Selective Electrodes (ISE) - The key feature of an ideal ISE is a thin membrane across which only the intended ion can migrate. Other ions can not cross the membrane. - The migration of ions from one side of the membrane to the other side through a selective binding with some sites within the membrane creates potential difference. Types of ISE 1. Glass membrane (pH electrodes) 2. Solid-state electrodes (F electrodes using a doped LaF3 crystal) 3. Liquid-based electrodes (Ca2+ electrode using a liquid chelator) 4. Compound electrode (CO2 gas sensing electrodes) Ion-exchange equilibrium A pH electrode responds selectively to H+, and not to to other ions, is that H+ is the only ion that binds significantly to the hydrated gel layer. Errors in pH measurement 1. The pH of Standards: +/-0.01 pH unit. 2. Junction potential: differences between standard and analyte solution. Errors 1 and 2 limits the accuracy of pH measurement to +/-0.02 pH. 3. Junction potential drift: the decay of the Ag|AgCl reference electrode. 4. Sodium error (alkaline error): respond to Na+ when [H+] is low, pH(exp) pH(real). 5. Acid error. The glass surface is saturated with H+, therefore, pH(exp) pH(real). 6. Equilibrium time: 30 s with adequate stirring. 7. Hydration time: hours soaking before making measurements. 8. Temperature Glass electrode A typical pH combination electrode, incorporating both glass and reference electrodes in one body. Solid-state electrode Employing an inorganic salt crystal doped with a small amount of ions of a different valency to create vacant sites. Liquid-based ion-selective electrode Consist of a polymeric support matrix of a material such as PVC or silicone rubber that contains a solvent and ion exchanger, usually a chelating agent, selective to the species to be determined. Selectivity coefficient of ion-selective electrodes The relative response of the electrode to different species with the same charge: Advantages of ISE 1. Linear response: over 4 to 6 orders of magnitude of current 2. Non-destructive: no consumption of analyte 3. Non-contaminating 4. Short-response time: in seconds or minutes, suitable for industrial applications 5. Unaffected by color or turbidity Limitations of ISE 1. Precision is rarely better than 1% 2. Electrodes can be fouled by proteins or other organics. 3. Interference by other ions 4. Electrodes are fragile and have limited shelf life. 5. Electrodes respond to the activity of uncomplexed ion; ligands must be absent or masked. Advances of ISE 1. Potentiometric biosensors: immobilization of an enzyme on a membrane. 2. Coated-wire electrodes: cheap and disposable miniaturization. 3. Ion-selective field-effect transistors (Ch 15-7). Electrolysis A reaction is driven in its non-spontaneous direction by an imposed electric current. Coulometry Based on the number of electrons used in a chemical reaction. Electrogravimetry The analyte is electrochemically deposited as a solid on an electrode. The increase in the mass of the electrode tells us how much analyte was present. E° and the Equilibrium Constant A galvanic cell produces electricity because the cell reaction is not at equilibrium. When a battery runs down to 0 V, the chemicals inside have reached equilibrium and the battery is "dead". Electrochemical Cells as Chemical Probes If a galvanic cell has a non-zero voltage, then the net cell reaction is not at equilibrium. However, we do allow the half-cells to stand long enough to come to equilibrium within each half-cell. Why we use mercury electrode in polarography? - When voltammetry is conducted with a dropping-mercury electrode, it is called polarography. - In polarography, the current between mercury working electrode and an inert auxiliary electrode (Pt) is measured. Voltage is applied between the Hg electrode and a reference electrode. A. More reproducible surfaces B. Operates at more negative potentials than can most other electrodes. C. Amalgamation with heavy metals (e.g., lead and cadmium) Problems with mercury? A. Highly toxic B. Difficult to handle C. Easily oxidized Polarogram Graph of current versus potential obtained in polarographic measurements. Diffusion current The limiting current when the rate of reduction is controlled by the rate of diffusion of species to the electrode. Potential sweep technique Scanning a chosen region of potential and measuring the current response arising from the electron transfer and associated reactions that occur. Cyclic voltammograms - The basic response to a linear sweep of potential is a peak-shaped curve - The current begins to rise to as the potential are reached where electrode reactions can occur (AB). This creates a concentration gradient that sucks in more electroactive species until depletion effects set in and the current begins to fall again. (BC). If the fuel efficiency of an automobile is 22 miles per gallon, what is its fuel efficiency in Kilometers per liter? ( 1Km= 0.621 mile, 1.00 L=1.057 quarts and 4 quarts = 1 gallon) 9.4 Km/L *What is the correct answer to the following expression: (49.1 - 42.61 ) x 13.1? 85 An intensive property of a substance is independent of amount. True Lithium has two stable isotopes with masses of 6.01512 amu and 7.01600 amu. The average atomic mass of Li is 6.941 amu. What is the percent abundance of each isotope? 7.493% Li-6 and 92.51% Li-7 C3H8 + O2 -- CO2 + H2O (unbalanced) How many grams of oxygen are required to burn 36.0 grams of C3H8? 131 g *There are __________ mol of bromide ions in 0.500 L of a 0.500 M solution of AlBr3 We put 0.250 - WRONG FIGURED OUT 0.75 Aluminum reacts with chlorine to produce aluminum chloride. If 2.00 moles of Al reacts with excess Cl2, how many grams of AlCl3 can be formed? Al + Cl2 ----- AlCl3 . ( unbalanced) 266 g A mixture of MgCO3 and MgCO3.3H2O has a mass of 2.883 g. After heating to drive off all the water the mass is 2.427 g. What is the mass percent of MgCO3.3H2O in the mixture? 40.4 A precipitation is expected when an aqueous solution of sodium iodide is added to an aqueous solution of Mercury(I) chloride For the reaction Pb(s) + PbO2(s) + 2 H+(aq) + 2HSO4-(aq) --2PbSO4(s) + 2H2O(l) The oxidizing agent ( be specific) is ________ Pb in PbO2 Based on the equations below, which metal is the least active? Pb(NO3)2(aq) + Ni (s) -- Ni(NO3)2 (aq)+ Pb(s) Pb(NO3)2(aq) + Ag(s) -- No reaction Cu(NO3)2(aq) + Ni(s) -- Ni(NO3)2(aq) + Cu(s) Cannot be determined Calculate the molarity of the solution that contains 40.0 g of NaOH in 100. mL of solution 10.0 M *What volume of 0.150 M H2SO4 is required to titrate 50.0 mL of 1.00 M NaOH? 167 mL How many chloride ions (Cl-1) are present in 83.6 g FeCl3? I put 3.10 x 10^23 - WRONG FOUND 9.31 x 10^23 Which of the following particles will not be deflected by charged plates? γ (gamma) particle TO KNOW: alpha particle = positive beta particle = negative gamma particle = no charge alpha flow towards negative side beta flow towards positive side SO, the gamma (neutral) particle is answer 0.314 g of oxalic acid dihydrate (MM = 126 g/mole) is neutralized by 28.5 mL NaOH solution. Find the concentration of NaOH. H2C2O4 + NaOH -- Na2C2O4 + H2O (unbalanced) 0.175 M What is the percentage of mass of oxygen in the compound C8H8O2? 23.5% *A sample of 16.0 g of ozone, O3, contains the same number of atoms as 58.7 g of nickel If 100.0 g of O2 are mixed with 20.0 g of H2 and the mixture is ignited, what mass of water is produced? 113 g When 0.926 g of a metal oxide is heated, the compound decomposes in the reaction shown below. 2 M2O(s) -- 4 M (s) + O2(g) If 0.06390 g O2 is produced, what is the identity of the metal? Ag *Which of the following is a nonelectrolyte in aqueous solution? I put HF - WRONG maybe ethanol - C2H5OH Don't know correct answer Which of the following is not correctly matched ZnO zinc (II) oxide Which of the following statements is false All redox reactions are also single displacement reactions *A solution of acetic acid, CH3COOH is 60.0 % by mass and has a density of 1.10 g/mL. Calculate the molarity (M) of the solution. 11.0 M Nitrogen dioxide (NO2) is a gas that enters the atmosphere principally from natural fertilizer breakdown. Some studies have shown that the isotope ratios of N-15( 15N) to N-14 (14N) and of O-18( 18O) to O-16 (16O) in NO2 depend on the source, which can thus be determined by measuring the relative abundance of molecular masses in a sample of NO2. What molecular masses are Not possible for NO2? 52 *A unknown compound contains only carbon, hydrogen and oxygen. Combustion of 1.00 g this compound will produce 0.4093 g H2O and 1.499 g CO2. What is the empirical formula of this unknown compound? C3H4O3 What is the net ionic equation for the reaction of sodium hydroxide with iron (III) nitrate? Fe3+ (aq) + . 3 OH- (aq) -- Fe(OH)3(s) You mix 50.0 mL of 0.165 M AgNO3 with 25.0 mL of 0.302 M KCl. What is the mass of the precipate that can be formed 1.08 g One of the outermost electrons in a strontium ( Sr) atom in the ground state can be described by which of the following sets of four quantum numbers? 5,0,0,1/2 NO2 is a known air-pollutant resulting from the combustion of petroleum in vehicles. Suppose at 6:00 am, there are 0.920 ppm NO2 in a liter of air. Calculate the mass (in grams) of the NO2 present in a liter, assuming there are 2.46 x 1023 molecules of air in 1.00 L. 1.73 x 10^-5 At 20°C, sample of gas has a volume of 2.51 L at 795 torr. What is the new pressure (in atm) if the volume is increased to 3.23 L at the same temperature? 0.813 Aluminum and oxygen react to form aluminum oxide. How many L of oxygen at 23°C and 1.4 atm of pressure are necessary to form 3.25 g of aluminum oxide? 0.83 The density of an unknown gas is 0.350 g/L at 40.00°C. If the gas occupies 30.3 L and has a pressure of 2.22 atm at 40.00°C, what is the molecular weight of the gas? The value of R = 0.0821 L-atm/mole-K 4.05 Determine the heat of reaction for the process TiO2(s) + 4HCl(g) -- TiCl4(l) + 2H2(g) + O2(g) using the information given below: Ti(s) + O2(g) -- TiO2(s) DH° = -939.7 kJ 2HCl(g) -- H2(g) + Cl2(g) DH° = -184.6 kJ Ti(s) + 2Cl2(g) -- TiCl4(l) DH° = -804.2 kJ -233.7 Which of the following sets of quantum numbers is not permissible? n =3, l = 3, m = -3, s = - ½ Commercial cold packs consist of solid ammonium nitrate and water. NH4NO3 absorbs 330 J of heat per gram dissolved in water. In a coffee-cup calorimeter, 3.00 g NH4NO3 is dissolved in 100.0 g of water at 24.0°C. What is the final temperature of solution? Assume that the solution has a specific heat capacity of 4.18 J/g°C. 21.7 What is the energy of a single photon with a wavelength of 633 nm? 3.14 x 10^-19 J Which statement below is false? The higher the frequency of light , the longer the wavelength The standard enthalpies of formation for substances are given below: Substance KJ/mole FeS2(s) -178.2 FeCl2 -341.8 FeCl3 (s) -399.5 HCl(g) -92.3 H2S(g) -20.6 HCl(aq) -167.1 H2O (g) -271.8 Calculate the Delta H for the reaction below. 2FeS2(s) + 8HCl(g) -- 2FeCl3(s) + 4H2S(g) + Cl2(g) 213.4 The Pauli's exclusion principle requires that No two electrons in the same atom can have the same set of four quantum numbers The magnetic property of Fe2+ is paramagnetic with four unpaired electrons Which of the following atoms has the largest atomic radius? K Which of the following elements has the smallest ionization energy? Mg Which of the following types of radiation has the longest wavelength? radio What is the maximum number of orbitals when n = 6 and l =2? 5 What is the major shortcoming of the Bohr Model? It does not deal with multi-electron atoms. From a consideration of electronic configurations, which of the elements indicated below would be classified as a transition element? 1s2, 2s2, 2p6, 3s2, 3p6, 3d5, 4s2 Calculate the most probable root mean square velocity of Oxygen gas at STP 461 m/s Non-ideal behavior for a gas is most likely to be observed under condition of ? low temperature and high pressure The sign of delta (change) H for the process H2O (g) -- H2O (l) is_________________ negative, and the process is exothermic Calculate the wavelength of the line in the Lyman series that results from the transition n =5 to n=1. 95.0 nm Determine the volume (in L) of Cl2(g) required to carry out the following reaction at 794 torr and 625°C using 15.0 g of Fe. The value of R = 0.0821 L-atm/mol-K. 2Fe(s) + 3Cl2(g) -- 2FeCl3(s) 28.4 The enthalpies of formation of various iodine species are as follows: I(g) Hf = 107 KJ/mole *=delta (change) I2(g) Hf = 21 KJ/mole HI (g) Hf = 26 KJ/mole What other additional information is needed to calculate the enthalpy of the following reaction? H2(g) + I2(g) --2HI (g) none, because the enthalpy of formation of an element in its stablest form is zero Which of the following chemical equations refers to the second ionization of Ca? Ca + (g) -- Ca 2+ (g) + e - Ammonia (NH3) gas is synthesized by its elements. If 2.50 L N2 react with 7.00 L H2, what is the theoretical yield ( in liter) of NH3 at 748 torr and 38 ∘C 4.67 L A small piece of Zn reacts with dilute HCl solution to form H2, which is collected over water at 16C into a large flask. The total pressure is measured at 752 torr, and the volume is 1495 mL, and the water vapor pressure is equal to 13.6 torr. calculate the mass of H2 0.124 g *Place the following in order of increasing bond length C-S C-Cl C-F Place the following in order of decreasing magnitude of lattice energy K2O Rb2S Li2O Li2O K2O Rb2S Choose the best Lewis structure for XeI2. C Choose the best Lewis structure for SO42⁻ (the smallest formal charge). Sorry, the choices are D,E,A,B,C. A (four sticks, one lone pair on the S) Which of the following resonance structures for OCN⁻ will contribute most to the correct structure of OCN- ? O(3 lone pairs)--C≡N(with 1 lone pair) Draw the best Lewis structure for Cl3-. What is the formal charge on the central Cl atom? -1 Using periodic trends, place the following bonds in order of increasing ionic character. S-F Se-F O-F O-F S-F Se-F Place the following in order of decreasing XO bond length, where "X" represents the central atom in each of the following compounds or ions. SiO32- CO2 CO32⁻ SiO32⁻ CO32⁻ CO2 Use the bond energies provided to estimate ΔH°rxn for the reaction below. CH3OH(l) + 2 O2(g) → CO2(g) + 2 H2O(g) ΔH°rxn = ? Bond. Bond Energy (kJ/mol) C-H 414 C-O 360 C=O 799 O=O 498 O-H 464 -392 KJ Choose the bond below that is most polar H-F Which molecule contains a triple bond? N2 Predict qualitatively the relative bond lengths of the four single bonds given below and arrange them from shortest to longest: C-N N-O N-Si O-O O-O N-O C-N N-Si What is the formal charge on sulfur in SO2 (assuming octet rule holds)? +1 Construct correct Lewis dot structures for the three molecules below. Determine which compounds, if any, exceed the octet rule. CF4 SF4 ClF3 I II III II and III Write the correct Lewis structure for XeF4. This molecule exceeds the octet rule. Determine the number of bonding pairs and lone pairs on the central atom. 4 bonding pairs and 2 lone pairs Using VSEPR Theory, predict the correct molecular shapes for NH3 and CO32- trigonal pyramidal, trigonal planar Using VSEPR Theory, predict the X-A-X angles for the following compounds. CO2, GeF4, BCl3 180°, 109.5°, 120° *Which of the following compounds does have tetrahedral molecular geometry? NO2- OR CCl4 Don't know - question was regraded and says we got no2- right but also said ccl4 was right Which of the following compounds does not have tetrahedral electron-pair geometry? (a) ccl4 (b) no2- (c) h3o+ (d) pcl3 (e) h20 (B) Label the hybridization at C#1, C#2, C#3, and C#4 in the molecule (B) sp sp sp2 sp3 Determine the hybridization around each central atom.] NO2 - CO2 NO3 - sp2 sp sp2 A molecule can be polar under which conditions? all of them. (when it has a permanent dipole when it does not have nonpolar bonds when it is not symmetrical when it has polar bonds) For molecules of the general formula AB n . . . n can be greater than four __________. only when A is an element from the third period or below the third period There are __________ σ bonds and __________ π bonds in H3C - CH2 - CH = CH - CH2 - C (triple bond) CH 16, 3 For Questions #25 and #26, you need to determine name of molecular shape, polarity and type of hybridization of the species BrF3 T-shaped, polar, sp3d See direction on question #25 SF5 - square pyramid, polar and sp3d2 Choose the correct description about XeF2, BCl3 and HCN HCN is the only polar compound Which of the following compounds would be expected to have the strongest ionic bonds? CsF The carbonate ion is known to be planar with all the oxygen atoms equidistant from the central carbon atoms. One the basis of these facts, which of the following conclusions are true concerning this ion? I. It can be represented by three equivalent resonance structures II. The carbon atom is sp2 hybridized III. The dipoles associated with each C-O bond are equal in magnitude. I, II and III