Chem 112 final exam practice questions and correct detailed answers

Define thermal energy. A) energy associated with the motion of an object B) energy associated with the temperature of an object C) energy associated with the force of an object D) energy associated with the gravity of an object E) energy associated with the position or composition of an object - correct answers B ) Identify an element that is NOT in its standard state. A) Hg(g) B) N2(g) C) O2(g) D) C(s) E) Ne(g) - correct answers A In which of the following substances should hydrogen bonding contribute to the attractive interactions in the molecules? A) HF B) HI C) H2S D) N(CH3 )3 E) None - correct answers A Convert 1.50 atm to torr. A) 760 torr B) 875 torr C) 1140 torr D) 1000 torr E) 1520 torr - correct answers C The volume of a gas is proportional to number of moles of a gas is known as A) Boyle's Law B) Ideal Gas Law C) Charles's Law D) Avogadro's Law E) Dalton's Law. - correct answers D Which of the following samples has the greatest density at STP? A) SO2 B) Xe C) NO2 D) SF6 E) All samples have the same density at STP. - correct answers D ) This equation is used to calculate the properties of a gas under non-ideal conditions. A) Avogadro's Law B) van der Waals equation C) Boyle's Law D) Dalton's Law - correct answers B The total pressure of a gas mixture is the sum of the partial pressure of its components is known as A) Avogadro's Law. B) Dalton's Law. C) Charles's Law. D) Ideal Gas Law. - correct answers B What type of intermolecular force causes the dissolution of NaF (an anticavity agent found in toothpaste) in water? A) ion-dipole force B) dipole-dipole forces C) hydrogen bonding D) dispersion forces - correct answers A A solution containing less than the equilibrium amount is called A) a dilute solution. B) an unsaturated solution. C) a supersaturated solution - correct answers B A reaction has a ∆H of +148.5 kJ/mol. Is the reaction exo- or endothermic? A) Endothermic B) Exothermic C) Not enough information to determine. - correct answers A Sublimation is defined as the phase transition from: A) gas to liquid B) gas to solid C) liquid to solid D) liquid to gas E) solid to gas - correct answers E Give the temperature and pressure at STP. A) 32 F and 1 torr Hg B) 0°C and 1.00 atm C) 25 °C and 1.00 atm D) 0 K and 1.00 atm - correct answers B The rate of effusion of two different gases is known as A) Avogadro's Law. B) Dalton's Law. C) Charles's Law. D) Boyle's Law. E) Graham's Law. - correct answers E A chemical reaction occurs in several steps. Identify the rate-determining step. A) the slowest step B) the fast step C) always the last step D) always the second step - correct answers A Which of the following processes have a ΔS 0? A) water freezes B) methyl alcohol condenses C) carbon dioxide(g) → carbon dioxide(s) D) All of the above processes have a ΔS 0. - correct answers D ) Identify a heterogeneous catalyst. A) Pd in H2 gas B) KI dissolved in H2O2 C) H2SO4 with concentrated HCl - correct answers A Which substance below has the strongest intermolecular forces? A) A2X, ΔHvap= 59.6 kJ/mol B) BY2 , ΔHvap= 26.7 kJ/mol C) CX2 , ΔHvap= 36.4 kJ/mol - correct answers A Identify the characteristics of a solid. A) indefinite shape and volume B) indefinite shape, but definite volume C) definite shape and volume - correct answers C Give the term for the amount of solute in moles per liter of solution. A) molality B) mass percent C) mole fraction D) mole percent E) molarity - correct answers E Reaction rates can change with A) temperature B) addition of a catalyst C) reactant concentrations D) all of these factors - correct answers D Parts per million requires a multiplication factor of A) 10-9 B) 10-3 C) 103 D) 1015 E) 106 - correct answers E Which compound should have the largest lattice energy? A) MgCl2 B) AlP C) NaI D) CaO E) KF - correct answers B Given the following rate law, how does the rate of reaction change if the concentration of X is tripled? Rate = k [X]3 [Y]2 A) The rate of reaction will increase by a factor of 5. B) The rate of reaction will increase by a factor of 27. C) the rate of reaction will increase by a factor of 8. D) The rate of reaction will increase by a factor of 3. E) The rate of reaction will remain unchanged. - correct answers B Pick the compound with the highest boiling point. A) HF B) HBr - correct answers A Which one of the following has a low density? A) gas B) liquid C) solid D) none E) all - correct answers A Which one of the following has a definite shape and volume? A) gas B) liquid C) solid D) none - correct answers C How is pressure-volume work calculated? A) w = P-∆V B) w = P∆V C) w = P+∆V D) w = -P∆V - correct answers D Which statement is false? A) An exothermic reaction gives heat off heat to the surroundings. B) Enthalpy is the sum of a system's internal energy and the product of pressure and volume change. C) ΔErxn is a measure of heat. D) ΔHrxn is the heat of reaction. E) An endothermic reaction has a positive ΔH. - correct answers C Which of the following signs on q and w represent a system that is doing work on the surroundings, as well as gaining heat from the surroundings? A) q = +, w = - B) q = -, w = + C) q = +, w = + D) q = -, w = - - correct answers A At atmospheric pressure, dry ice A) freezes B) deposits C) sublimes D) melts E) boils - correct answers C Given w = 0, an endothermic reaction has the following. A) +ΔH and -ΔE B) - ΔH and +ΔE C) + ΔH and +ΔE D) - ΔH and -ΔE - correct answers C Which of the following processes is exothermic? A) ionization of a K atom B) breaking of a Br-Br bond C) sublimation of dry ice (CO2 (s)) D)formation of an ionic compound (salt) E) All of the above processes are exothermic. - correct answers D Define boiling. A) the phase transition from solid to gas B) the phase transition from gas to solid C) the phase transition from gas to liquid D) the phase transition from liquid to gas - correct answers D 5) Which of the following statements is true? A) State functions do not depend on the path taken to arrive at a particular state. B) ΔErxn can be determined using constant volume calorimetry. C) ΔHrxn can be determined using constant pressure calorimetry. D) All of the above are true. - correct answers D ) Which of the following substances (with specific heat capacity provided) would show the greatest temperature change upon absorbing 100.0 J of heat? A) 10.0 g Cu, CCu = 0.385 J/g°C B) 10.0 g H2O, CH2O = 4.18 J/g°C C) 10.0 g ethanol, Cethanol = 2.42 J/g°C D) 10.0 g Pb, CPb= 0.128 J/g°C - correct answers B Give the change in condition to go from a liquid to a gas. A) cool or increase pressure B) increase heat or increase pressure C) increase heat or reduce pressure D) cool or reduce pressure - correct answers C At atmospheric pressure, ice A) freezes B) deposits C) sublimes D) melts E) boils - correct answers D Which statement is true about an exothermic reaction? A) Exothermic reaction gives off heat to the surroundings. B) An exothermic reaction feels warm to the touch. C) Both statements above are true. - correct answers C Define hypoxia. A) oxygen starvation B) increased oxygen concentration in body tissues C) increased nitrogen concentration in body tissues and fluids D) nitrogen starvation - correct answers A Which one of these gases will diffuse the fastest at 25°C? A) He B) Ar C) N2 D) Ne E) O2 - correct answers A The law of ________ states that energy can be neither created nor destroyed. A) kinetic energy B) thermochemistry C) potential energy D) the conservation of energy - correct answers D Define thermal energy. A) energy associated with the temperature of an object B) energy associated with the motion of an object C) energy associated with the force of an object D) energy associated with the gravity of an object E) energy associated with the position or composition of an object - correct answers A The instrument used to measure the pressure of a gas in a laboratory setting is called a A) barometer B) manometer C) sphygmomanometer D) spectrophotometer - correct answers B Which of the following samples will have the greatest volume at STP? A) 16 g Ne B) 16 g He C) 16 g Cl2 D) All of these samples would have the same volume at STP. - correct answers B Give the temperature and pressure at STP. A) 0°C and 1.00 atm B) 0 K and 1.00 atm C) 25°C and 1.00 in Hg D) 32K and 1 torr Hg - correct answers A Which of the following will cause the volume of an ideal gas to triple in value? A) raising the temperature from 25°C to 75°C at constant pressure B) lowering the absolute temperature by a factor of 3 at constant pressure C) raising the absolute temperature by a factor of 3 while increasing the pressure by a factor of 3 D) lowering the absolute temperature by a factor of 3 while increasing the pressure by a factor of 3 E) lowering the pressure by a factor of 3 while the temperature stays constant - correct answers E Three identical flasks contain three different gases at standard temperature and pressure. Flask A contains Cl2; flask B contains O3 ; and flask C contains F2 . Which flask contains the largest number of moles? A) flask A B) flask B C) flask C D) All contain same number of moles. - correct answers D Which of the following gases will behave least like an ideal gas at low temperatures? A) He B) N2 C) H2 D) CO2 - correct answers D A solid can be purified through what technique? A) recrystallization B) dilution C) dissolution D) boiling E) melting - correct answers A ) Place the following substances in order of decreasing boiling point. H2O N2 CO A) CO H2O N2 B) N2 CO H2O C) H2O CO N2 D) CO N2 H2O E) N2 H2O CO - correct answers C Give the term for the amount of solute in moles per liter of solution. A) molality B) molarity C) mole fraction D) mole percent E) mass percent - correct answers B A solution containing more than the equilibrium amount is called A) an unsaturated solution B) a dilute solution C) a supersaturated solution D) a concentrated solution - correct answers C ) The boiling point of H2O is much higher than that of H2S. This is mostly due to A) dispersion forces being much stronger in H2S than in H2O. B) dipole-dipole forces being much stronger in H2S than in H2O. C) hydrogen bonding being much stronger in H2S than in H2O. D) dipole-dipole forces being much stronger in H2O than in H2S. E) hydrogen bonding being much stronger in H2O than in H2S. - correct answers E Which of the following compounds is most soluble in hexane? A) H3C-OH B) H3C-CH2-OH C) H3C-CH2-CH2-CH3 D) H3C-CH2-CH2-CH2-CH2-CH3 - correct answers D In which of the following substances should hydrogen bonding contribute to the attractive interactions in the molecules? A) CF4 B) HI C) H2Se D) N(CH3 )3 E) None of the above - correct answers E What is the overall reaction order for the reaction that has the rate law: Rate = k[O2 ][NO ] 2 ? A) zero order B) first order C) second order D) third order - correct answers D The resistance of a liquid to flow is known as A) surface tension B) meniscus C) viscosity D) capillary action E) intermolecular forces. - correct answers C What is the strongest type of intermolecular force present in H3C-F? A) dispersion B) dipole-dipole C) hydrogen bonding D) ion-dipole - correct answers B What type of intermolecular force causes the dissolution of NaCl in water? A) hydrogen bonding B) dipole-dipole forces C) ion-dipole force D) dispersion forces E) none of the above - correct answers C ) Which of the following compounds exhibits hydrogen bonding? A) CH3 I B) HBr C) H3C-O-CH3 D) H3C-NH2 - correct answers D What is the strongest type of intermolecular force present in Cl2? A) ion-dipole B) dipole-dipole C) dispersion D) hydrogen bonding - correct answer