CHM 130 EXAM #1 Questions With 100% Verified Correct Answers

What properties distinguish solids from liquids? Liquids from gasses? Solids from gasses? - correct answers Liquids can change their shape (flow); solids can't. Gasses can undergo large volume changes as pressure changes; liquids do not. Gasses flow and change volume; solids do not. How does a homogeneous mixture differ from a pure substance? How are they similar? - correct answers The mixture can have a variety of compositions; a pure substance has a definite composition. Both have the same composition from point to point. How do molecules of elements and molecules of compounds differ? In what ways are they similar? - correct answers Molecules of elements contain only one type of atom; molecules of compounds contain two or more types of atoms. They are similar in that both are comprised of two or more atoms chemically bonded together. Classify each of the following changes as physical or chemical: (a) Condensation of steam: (b) Burning of gasoline: (c) Souring of milk: (d) Dissolving of sugar into H20: (e) Melting of gold: - correct answers (a) Condensation of steam: physical (b) Burning of gasoline: chemical (c) Souring of milk: chemical (d) Dissolving of sugar into H20: physical (e) Melting of gold: physical Explain the difference between extensive properties and intensive properties. - correct answers The value of an extensive property depends upon the amount of matter being considered, whereas the value of an intensive property is the same regardless of the amount of matter being considered. Express each of the following numbers in exponential notation with correct significant figures: (a) 704: (b) 0.03344: (c) 547.9: (d) 22086: (e) 1000.00: (f) 0.: (g) 0.007157: - correct answers (a) 704: 7.04 x 10^2 (b) 0.03344: 3.344 x 10^-2 (c) 547.9: 5.479 x 10^2 (d) 22086: 2.2086 x 10^4 (e) 1000.00: 1.00000 x 10^3 (f) 0.: 6.51 x 10^-8 (g) 0.007157: 7.157 x 10^-3 How many significant figures are contained in each of the following measurements? (a) 53 cm: (b) 2.05 × 108 m: (c) 86,002 J: (d) 9.740 × 104 m/s: 4 and (e): (e) 10.0613 m3: (f) 0.17 g/mL: (g) 0.88400 s: - correct answers (a) 53 cm: 2 (b) 2.05 × 108 m: 3 (c) 86,002 J: 5 (d) 9.740 × 104 m/s: 4 and (e): 6 (e) 10.0613 m3: 6 (f) 0.17 g/mL: 2 (g) 0.88400 s: 5 Round off each of the following numbers to two significant figures: (a) 0.436: . (b) 9.000: (c) 27.2: (d) 135: (e) 1.497 × 10-3 (f) 0.445: - correct answers (a) 0.436: .44 (b) 9.000: 9.0 (c) 27.2: 27 (d) 135: 140 (e) 1.497 × 10−3: 1.5 x 10-3 (f) 0.445: .44 #53 Perform the following calculations and report each answer with the correct number of significant figures: (a) 628 × 342: (b) (5.63 × 102) × (7.4 × 103): (c) 28.0/13.483: (d) 8119 × 0.000023: (e) 14.98 + 27,340 + 84.7593: (f) 42.7 + 0.259: - correct answers (a) 628 × 342: 2.15 x 10^5 (b) (5.63 × 102) × (7.4 × 103): 4.2 x 10^6 (c) 28.0/13.483: 2.08 (d) 8119 × 0.000023: .19 (e) 14.98 + 27,340 + 84.7593: 27,440 (f) 42.7 + 0.259: 43.0 Write conversion factors (as ratios) for the number of: Yards in 1 meter = Liters in 1 liquid quart = Pounds in 1 kilogram = - correct answers Yards in 1 meter = 1.09361 yds / 1 m Liters in 1 liquid quart = 0.946353 L / 1 qt Pounds in 1 kilogram = 2.20462 lbs / 1 kg How many milliliters of a soft drink are contained in a 12.0-oz can? - correct answers 12 oz x 29.5735 mL / 1 oz = 354.882 - 355 mL The diameter of a red blood cell is about 3 × 10−4 in. What is its diameter in centimeters? - correct answers 3 x 10^-4 inch x 2.54 cm / 1 inch = 7.62 x 10^-4 = 8 x 10^-4 (a) the length of a soccer field, 120 m (three significant figures), to feet - correct answers 120 m x 3.24 ft / 1 m = 393.6 = 394 (b) the height of Mt. Kilimanjaro, at 19,565 ft, the highest mountain in Africa, to kilometers - correct answers 19,565 ft x 1 km / 3280.84 ft = 5.9634 km (c) the area of an 8.5- × 11-inch sheet of paper in cm2 - correct answers 93.5 inch x 6.4516 cm^2 / 1 inch = 603.2246 = 6.0 x 10^2 (d) the displacement volume of an automobile engine, 161 in.3, to liters - correct answers 8.63 × 10−5 kg (e) the estimated mass of the atmosphere, 5.6 × 1015 tons, to kilograms - correct answers 3.76 ×× 10−1 m (f) the mass of a bushel of rye, 32.0 lb, to kilograms - correct answers 5.4 × 10−5 m; (g) the mass of a 5.00-grain aspirin tablet to milligrams (1 grain = 0.00229 oz) - correct answers 5.4 ×× 10−5 m Calculate the density of aluminum if 27.6 cm3 has a mass of 74.6 g. - correct answers 74.6 g / 27.6 cm^3 = 2.7 g/cm^3 (a) What is the mass of 6.00 cm3 of mercury, density = 13.5939 g/cm3? - correct answers 6.00 cm^3 x 13.5939g g/cm^3 = 81.56 - 81.6 g (b) What is the mass of 25.0 mL octane, density = 0.702 g/cm3? - correct answers 25.0 mL x .702 g/cm^3 = 17.55 = 17.6 g (a) What is the volume of 25 g iodine, density = 4.93 g/cm3? - correct answers 25 g / 4.93 g/cm^3 = 5.07 = 5.1 mL (b) What is the volume of 3.28 g gaseous hydrogen, density = 0.089 g/L? - correct answers 3.28 g / .089 g/L = 36.5 = 37