CHEM103 / CHEM 103 Module 1 Exam Questions & Answers | Latest 2026–2027 Update | General Chemistry I with Lab | Portage Learning | Verified Solutions | Grade A

CHEM103 / CHEM 103 Module 1 Exam Questions & Answers | Latest 2026–2027 Update | General Chemistry I with Lab | Portage Learning | Verified Solutions | Grade A 2026 / 2027 Academic Year Q: How many ounces are in a pound? Answer 16 Q: How many quarts are in a gallon? Answer 4 Q: K to °C Answer K (larger) - 273 = °C (smaller) Q: °C to K Answer °C (smaller) + 273 = K (larger) Q: °F to °C Answer (°F - 32) / 1.8 = °C Q: °C to °F Answer (°C x 1.8) + 32 = °F Q: What is a way to remember Celsius to Fahrenheit conversion? Answer MA and SD are both US state abbreviations Q: All densities are dependent on_______ or ____________ Answer -molecular weights -atomic weights Q: density formula Answer D=m/v Q: define accuracy Answer the nearness of the measured value to the actual value of the quantity being measured. Q: define precision Answer degree of agreement between several measured values of a quantity. Q: What are rules for determining sig figs? Answer -All non-zero digits are significant. -All zeros between or following non-zero numbers are significant. -Zeros to the left of a decimal or preceding other non-zero numbers are not significant. Q: How many sig figs in 1000 Answer 1 Q: How many sig figs in 1000. Answer 4 Q: How do sig figs work in multiplication or division calculations? Answer The result should be rounded off so as to contain the same number of significant figures as the measurement with the least number of significant figures Q: 128.61 / 51.20 (sig figs) Answer 2.512 Q: How do sig figs work in addition or subtraction calculations? Answer the result should be rounded off so that it has the same number of decimal places as the measurement having the fewest decimal places Q: How do sig figs work in multi-step calculations? Answer -Calculated values should not be rounded until the very end of the calculation. However, you do need to keep track of significant figures as you go along. -the rules of the order of operations must be followed: PEMDAS Q: (5.625 + 8.15) x 2.34 + 3.2 Answer 35.4 -the last remaining digit is left as it is -Example: 12.4 is rounded to 12 (4 is less than 5) Q: Rounding rules: If the digit to be dropped is greater than 5... Answer -the last retained digit is increased by one. -Example: 12.6 is rounded to 13 (6 is greater than 5) Q: Rounding rules: If the digit to be dropped is less than 5... Answer Q: If the digit to be dropped is 5, and if any digit following it is not zero... the last remaining digit is increased by one. Answer -12.51 is rounded to 13 (digit to be dropped is 5 and 1 is not a zero) Q: If the digit to be dropped is 5 and is followed only by zeroes... Answer -the last remaining digit is increased by one if it is odd but left as it is if even. - Examples: 11.5 is rounded to 12 (5 is followed by zero and 11 is odd so increased by 1) -12.5 is rounded to 12 (5 is followed by zero and 12 is even so the last remaining digit is left as it is) -This rule means that if the digit to be dropped is 5 followed only by zeroes, the result is always rounded to the even digit. Q: 7.54 / 2.390 + 1.53 - 2.810 (sig figs and rounding) Answer 1.87 Q: 1.1 EXPONENTIAL NUMBERS Answer The speed of light is 186,000 miles per second. This is 1.86 x 105 (in exponential form) The diameter of an E. coli cell is 0. meters = 8.0 x 10-7 (in exponential form) . A number larger than one will have a positive exponent. Move the decimal point nine places to the left to give 4.95 x 109 0. A number smaller than one will have a negative exponent. Move the decimal point 13 places to the right to give 5.6 x 10-13 1.) 0. = smaller than 1 = negative exponent, move decimal 6 places = 4.56 x 10-6 2.) 2.63 x 107 = positive exponent = larger than 1, move decimal 7 places = . 3.) 7800000. = larger than 1 = positive exponent, move decimal 6 places = 7.8 x 106 4.) 8.26 x 10-5 = negative exponent = smaller than 1, move decimal 5 places = 0.0000826 5.) 5.38 x 10-3 = negative exponent = smaller than 1, move decimal 3 places = 0.00538 6.) 0.000673 = smaller than 1 = negative exponent, move decimal 4 places = 6.73 x 10-4 7.) 3.82 x 104 = positive exponent = larger than 1, move decimal 4 places = 38200. 8.) . = larger than 1 = positive exponent, move decimal 8 places = 6.23 X 108 Q: 1.2: METRIC SYSTEM - UNIT CONVERSIONS Answer 1 foot (ft)=12 inches (in) 1 kilogram (kg)=1000 grams (g) 1 pound (lb)=16 ounces (oz) 1 gallon (gal)=4 quarts (qt) 1000 milliliters (ml)=1 liter (L) 100 centigrams (cg)=1 gram (g) 10 decimeters (dm)=1 meter (m) Q: The prefixes kilo (= 1000), milli (= 1/1000), centi (= 1/100), and deci (= 1/10) Answer are used with any metric unit, such as grams (weight), liters (volume), and meters (distance). Q: The original quantity and unit (to be converted) are multiplied by a conversion factor (which is a fraction made up as follows): Answer New unit (on top) / Old unit (on bottom) 48 ounces = ? pounds 48 o z × 1 p o u n d / 16 o z = 3 p o u n d s Q: 4 kilograms = ? grams Answer 4 Kg X 1000 grams/1kg = 4000 grams 1.) 656 cm x 1 m / 100 cm = 6.56 m 2.) 20 gal x 4 qt / 1 gal = 80 qts 3.) 7820 ml x 1 liter / 1000 ml = 7.82 liters 4.) 36 g x 1000 mg / 1 g = 36000 mg 5.) 25.3 g x 10 dc / 1 g = 253 dg 6.) 6.2 m x 1000 mm / 1 m = 6200 mm 7.) 725 l x 1000 ml / 1 liter = 725,000 ml 8.) 56 ft x 12 in / 1 ft = 672 in Q: 1.3: TEMPERATURE CONVERSIONS Answer 1.) 132 oC + 273 = 405 oK 2.) 132 oF - 32 x 1.8 = 55.6 oC + 273 = 328.6 oK 3.) 285 oK - 273 = 12 oC 4.) 60 oC x 1.8 + 32 = 140 oF 5.) 85 oF - 32 x 1.8 = 29.4 oC 6.) 52 oC + 273 = 325 oK 7.) 32 oC x 1.8 + 32 = 89.6 oF 8.) 412 oK - 273 = 139 oC x 1.8 + 32 = 282.2 oF Q: K to °C(°C and K differ by 273) Answer K (larger) - 273 = °C (smaller) Q: °C to K(°C and K differ by 273) Answer °C (smaller) + 273 = K (larger) Q: °F to °C(Subtract 32, and divide by 1.8) Answer °F - 32 / 1.8 = °C Q: °C to °F(Multiply by 1.8, and add 32) Answer °C X 1.8 + 32 = °F Q: 1.4: DENSITY Answer Density represents the mass of a substance in a unit volume of that substance. The density of most solids or liquids is expressed in the unit grams per milliliter (or g/ml). Q: The following equation is used to calculate density if you know the mass (in grams) and the volume (in milliliters). Answer D (g/ml) = M(g) / V(ml) 1.) 35.6 ml = V 1.86 g/ml = D find M = D x V = 1.86 x 35.6 = 66.2 grams 2.) 13.6 g/ml = D 1000 g = M find V = M / D = 1000 / 13.6 = 73.5 ml 3.) 200 ml = V 620 g = M find D = M / V = 620 g / 200 ml = 3.10 g/ml Q: 1.5: SIGNIFICANT FIGURES Answer Rules for determining significant figures in a number: All non-zero digits are significant. All zeros between or following non-zero numbers are significant. Zeros to the left of a decimal or preceding other non-zero numbers are not significant. 4326.7 - This number contains 5 significant figures (in bold). 400.70 - This number contains 5 significant figures (in bold). 0.3267 - This number contains 4 significant figures (in bold). 0.0070 - This number contains 2 significant figures (in bold). 0.5070 - This number contains 4 significant figures (in bold). Q: The appropriate number of significant figures must be reported in any answer resulting from a calculation. The rules for reporting the correct number of significant figures in an answer depends on whether the calculation involved addition/subtraction or multiplication/division. In addition or subtraction calculations, the result should be rounded off (more about that later) so that it has the same number of decimal places as the measurement having the fewest decimal places (counting from left to right). Examples: Answer 8.612 + 4.51 + 0.20 + 3.9 = 17.222 = 17.2 (round off to tenths place because of 3.9) 47.60 - 23. = 24.60 = 25 (round off to the unit's place because of 23.) Q: In multiplication or division calculations, the result should be rounded off so as to contain the same number of significant figures as the measurement with the least number of significant figures. Examples: Answer 128.61 / 51.20 = 2.51191 = 2.512 (round off to 4 significant figures because of 51.20) 54.06 x 17.0 = 919.02 = 919 (round off to 3 significant figures because of 17.0) Q: Rules for rounding off numbers: Answer Wait until all operations (in a multiple-step problem) have been done before rounding off the final answer. If the digit to be dropped is greater than 5, the last retained digit is increased by one. For example, 12.6 is rounded to 13. If the digit to be dropped is less than 5, the last remaining digit is left as it is. For example, 12.4 is rounded to 12. If the digit to be dropped is 5, and if any digit following it is not zero, the last remaining digit is increased by one. For example, 12.51 is rounded to 13. If the digit to be dropped is 5 and is followed only by zeroes, the last remaining digit is increased by one if it is odd but left as it is if even. For example, 11.5 is rounded to 12, 12.5 is rounded to 12. Q: How many significant figures are there in each of the following numbers? 1.) 0.004035 contains 4 significant figures 2.) 306.2 contains 4 significant figures 3.) 20.70 contains 4 significant figures 4.) 0.3450 contains 4 significant figures 5.) 0.0231 contains 3 significant figures 6.) 45.670 contains 5 significant figures 7.) 0.00034 contains 2 significant figures 1.) (5.625 + 8.15) x 2.34 + 3.2 = Answer 35.4 (to tenths place, 3.2) 2.) 7.54 / 2.390 + 1.53 - 2.810 = Answer 1.87 (to hundredths place, 1.53 3.) (12.5340 - 8.350) / 4.76 + 8.35 = Answer 9.23 (to hundredths place, 8.35) 4.) What is the average of 0.1707, 0.1713, 0.1720, 0.1704, and 0.1715? = 0.17118= Answer 0.1712 5.) V = M/D = 1000 g / 13.6 g/ml = Answer 73.5 ml (division, density contains only 3 sig figs) 6.) D = M/V = 155 g / 50 ml = 3.1 g/ml (division, volume contains only 2 sig figs) Q: ALUMINUM Answer Al Q: ANTIMONY Answer Sb ARGON Answer Ar ARSENIC As BARIUM Ba BERYLLIUM Be BISMUTH Bi BORON B BROMINE Br CADMIUM Cd CALCIUM Ca CARBON C CHLORINE Cl CHROMIUM Cr COBALT Co COPPER Cu FLUORINE F GOLD Au HELIUM He HYDROGEN H IODINE I IRON Fe LEAD Pb LITHIUM Li MAGNESIUM Mg MANGANESE Mn MERCURY Hg NEON Ne NICKEL Ni NITROGEN N OXYGEN O PHOSPHORUS P PLATINUM Pt POTASSIUM K SILICON Si SILVER Ag SODIUM Na STRONTIUM Sr SULFUR S TIN Sn TITANIUM Ti TUNGSTEN W URANIUM U ZINC Zn Elements There are over 100 elements that are the basic materials from which all other classes of matter are derived. These elements are pure substances containing no other element and are listed in the periodic table of the elements Compounds A compound is an intimate combination of two or more elements in which the elements become attached to one another. Compounds can be recognized by their scientific name, which does not appear on the table of elements but contains the name (or part of the name) of two or more elements. Table salt is actually a compound called sodium chloride, and the names of two elements sodium and chlorine appear in the name of this compound. Homogeneous mixtures (also called solutions) A homogeneous mixture (solution) is a combination of two or more elements or compounds, which appears (to the eye) to be one layer or material. For instance, when salt (a compound) is added to water (actually the compound hydrogen oxide), the two materials mix with the salt dissolving (disappearing) to make a solution. Heterogeneous mixtures Yes - The material is an element. No - The material is a compound, solution, or heterogeneous mixture. A heterogeneous mixture is a combination of two or more elements or compounds, which appears (to the eye) to be more than one layer or material. For instance, when sand (a compound) is added to water (actually the compound hydrogen oxide), the sand settles in one layer on the bottom with the water forming another layer on top. Is the name of the material on the list of elements? Are the names (or part of the names) of two elements present in the scientific name of the material? Yes - The material is a compound. No - The material is a solution or a heterogeneous mixture. Is only one substance, layer, or color seen when I look at the material? Yes - The material is a solution. No - The material is a heterogeneous mixture. Are two or more substances, layers, or colors seen when I look at the material? Yes - The material is a heterogeneous mixture. 1.7: PHYSICAL AND CHEMICAL CHANGES Examples of physical changes are the processes of: melting freezing boiling (or evaporation) condensation dissolving Examples of chemical changes are the processes of: burning (or combustion) - heat/light evolved rusting (or oxidizing) - color change (gray steel to red rust) an explosion - gas evolved baking Water undergoes electrolysis to form hydrogen gas and oxygen gas Chemical 1.8: CHANGES IN TEMPERATURE Melting ice to liquid water requires heat to be added, so process is endothermic. Condensing steam to liquid water requires heat to be extracted, so the process is exothermic. Cooling liquid water from 25° to 20° requires heat to be extracted, so the process is exothermic. Burning natural gas gives off heat (and light as a flame), so process is exothermic. Applying an instant cold pack from an athletic trainer’s kit to the bruised knee of a soccer player extracts heat from the knee, so the process is exothermic. Calorimetry the study of how much heat is involved in a temperature or physical change Thermochemistry he study of how much heat is involved in a chemical change. 1.9: ATOMIC STRUCTURE All matter is composed of atoms, the most basic unit. You can think of an atom like our solar system with most its mass concentrated at the center and smaller objects orbiting around the central mass. The large central mass of the atom is called the nucleus and contains two types of particles called protons and neutrons. The protons have a positive (+) charge; the neutrons have no charge. The low-mass particles orbiting around the nucleus are called the electrons; they have a negative (-) charge. ATOMIC NUMBER # of protons = # of electrons ATOMIC CHARGE = (# of protons) - (# of electrons) = 0 ATOMIC WEIGHT # of protons + # of neutrons The atomic weight is the larger number associated with each element in the periodic table. isotopes Isotopes of an element have the same number of protons and electrons as one another, but they have differing numbers of neutrons. This means that they have the same atomic number and charge (0) but different mass numbers. IONIC CHARGE = (# of protons) - (# of electrons) = +n or -n 1.10: CHEMICAL NAMES - 1. Binary Ionic Compounds The name of an element is slightly modified when naming it as part of a binary (containing only two elements: a metal and a nonmetal) compound since the metal has become a positively charged ion (cation) and the nonmetal has become a negatively-charged ion (anion). Metal name + nonmetal stem + “ide” CHARGE OF A NONMETAL = (periodic table group # - 8) CHARGE OF A METAL = + (periodic table group #) O-2 oxide S-2 sulfide N-3 nitride Cl- chloride Cr+3 Chromium (III) Cr+6 Chromium (VI) Mn+2 Manganese (II) Mn+4 Manganese (IV) Mn+7 Manganese (VII) Fe+2 Iron (II) Fe+3 Iron (III) Cu+1 Copper (I) Cu+2 Copper (II) Sn+2 Tin (II) Sn+4 Tin (IV) Pb+2 Lead (II) Pb+4 Lead (IV) Hg+2 Mercury (II) Hg2+2 Mercury (I)* CaCl2 Calcium chloride Al2O3 Aluminum oxide K3P Potassium phosphide MnO2 Manganese (IV) oxide PbCl2 Lead (II) chloride Hg2I2 Mercury (I) iodide 2. Binary Molecular Compounds Compounds containing only two elements: a nonmetal and another nonmetal. # prefix 1st nonmetal name # prefix 2nd nonmetal stem “ide” The # prefixes used are: 1 = mono 2 = di 3 = tri 4 = tetra 5 = penta 6 = hexa 7 = hepta 8 = octa 9 = nona 10 = deca BCl3 Boron trichloride P2O3 Diphosphorus trioxide SF6 Sulfur hexafluoride N2O5 Dinitrogen pentoxide 3. Non-binary Ionic Compounds Compounds containing three or more elements: a metal and a poly-atomic group Metal name name of poly-atomic group (no # prefixes, no “ide” suffix) NH4+ ammonium NO2- nitrite NO3- nitrate OH- hydroxide CN- cyanide ClO- hypochlorite ClO2- chlorite ClO3- chlorate ClO4- perchlorate MnO4- permanganate C2H3O2- acetate SO3-2 sulf(ur)ite * SO4-2 sulf(ur)ate * CO3-2 carbonate CrO4-2 chromate Cr2O7-2 dichromate PO4-3 phosph(or)ate PO3-3 phosph(or)ite * CaSO4 Calcium sulfate Al(NO3)3 Aluminum nitrate K3PO4 Potassium phosphate 4. Acids - Binary acids (Compounds containing hydrogen and a nonmetal) “Hydro” + nonmetal stem + “ic acid” HCl Hydrochloric acid H2Se Hydroselenic acid Non-binary acids (Compounds containing hydrogen and a poly-atomic group) Stem of poly-atomic group ("ate" ending becomes "ic") acid Stem of poly-atomic group ("ite" ending becomes "ous") acid HNO3 Nitric acid HClO3 Chloric acid H2CrO4 Chromic acid Na2SO4 Sodium sulfate O2F2 Dioxygen difluoride Ca(NO3)2 Calcium nitrate HF Hydrofluoric acid K2Cr2O7 Potassium dichromate Ca3N2 Calcium nitride SnI4 Tin (IV) iodide Li3PO4 Lithium phosphate Cl2O7 Dichlorine heptoxide Fe(OH)3 Iron (III) hydroxide NiCO3 Nickel carbonate PF5 Phosphorus pentafluoride HNO2 Nitrous acid NH4NO3 Ammonium nitrate 1.11: WRITING CHEMICAL FORMULAS 1. Li+1 , SO4-2 = Li2SO4 2. Ba+2 , Cl-1 = BaCl2 3. Na+1 , PO4-3 = Na3PO4 4. Al+3 , S-2 = Al2S3 5. Sn+2 , OH-1 = Sn(OH)2 6. Pb+4 , O-2 = PbO2 (need just 2 Os to balance Pb) 7. Mg+2 , N-3 = Mg3N2 8. Ca+2 , CN-1 = Ca(CN)2 9. Sb+5 , O-2 = Sb2O5 10. K+1 , Br-1 = KBr H2SO3 sulfurous acid Ca(NO3)2 Calcium nitrate FeI2 Iron (II) iodidie Bromic acid nonbinary acid of H + bromate (BrO3-1) = HBrO3 Dinitrogen pentoxide - ide = binary, two N, 5 O = N2O5 Potassium carbonate K+1, CO3-2 = K2CO3 What are the three domains of chemistry? macroscopic, microscopic, symbolic macroscopic domain large enough to be sensed directly by human sight or touch Which domain of chemistry is a lead pencil? macroscopic domain microscopic domain realm of things that are too small to be sensed directly (can be seen using microscope) symbolic domain Language of chemistry: chemical symbols, formulas, calculations etc., that help chemists communicate about properties that cannot be observed. Which domain of chemistry is H20? symbolic domain Which domain of chemistry is a water bottle? macroscopic domain Which domain of chemistry is a carbon atom? microscopic domain Which domain of chemistry is Cu(s)? symbolic domain Which domain of chemistry is an electron? microscopic domain What are the three basic parts of a measurement? a number, a unit, and indication of uncertainty What is the difference between an exact number and an uncertain measurement? Exact number- derived from counting Uncertain number- derived from a measurement other than counting and subject uncertainty due to limitations of the measurement process used What are the 3 states of matter commonly found on earth? Solid- fixed shape and volume Liquid- takes the shape of the container, has a fixed volume, for horizontal surface Gas- takes shape and volume of container Explain the law of the conservation of matter The amount of matter involved in chemical or physical change must remain constant Who used a cathode ray tube to calculate the mass-to-charge ratio of cathode ray particles? JJ Thompson What particle did JJ Thompson ultimately discover? The electron Robert Millikan determined the charge of an electron using an "oil drop" experiment. Ernest Ruthorford ired