Name: ________________________ Class: ___________________ Date: __________ Chapter 10 test Matching Match each item with the correct statement below. a. representative particle d. percent composition b. mole e. standard temperature and pressure c. Avogadro's number f. empirical formula ____ ____ ____ ____ ____ ____ 1. 2. 3. 4. 5. 6. the number of representative particles of a substance present in 1 mole of that substance an atom, an ion, or a molecule, depending upon the way a substance commonly exists the SI unit used to measure amount of substance 0°C and 1 atm the percent by mass of each element in a compound the smallest whole number ratio of the atoms in a compound Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. ____ ____ 7. What SI unit is used to measure the number of representative particles in a substance? a. kilogram c. kelvin b. ampere d. mole 8. How many hydrogen atoms are in 5 molecules of isopropyl alcohol, C 3 H 7 O? a. ____ 5 × (6.02 × 10 23 ) c. 35 b. 5 d. 35 × (6.02 × 10 23 ) 9. All of the following are equal to Avogadro's number EXCEPT ____. a. the number of atoms of bromine in 1 mol Br 2 b. c. the number of atoms of gold in 1 mol Au the number of molecules of nitrogen in 1 mol N 2 d. the number of molecules of carbon monoxide in 1 mol CO ____ 10. How many moles of tungsten atoms are in 4.8 × 10 25 atoms of tungsten? 8.0 × 10 2 moles c. 1.3 × 10 −1 moles b. 8.0 × 10 1 moles d. ____ 11. How many atoms are in 0.075 mol of titanium? 1.3 × 10 −2 moles a. c. 6.4 × 10 2 b. 2.2 × 10 24 ____ 12. How many molecules are in 2.10 mol CO 2 ? d. 4.5 × 10 22 a. 2.53 × 10 24 molecules c. 3.49 × 10 −24 molecules b. 3.79 × 10 24 molecules d. 1.26 × 10 24 molecules a. 1.2 × 10-25 1 ID: A Name: ________________________ ID: A ____ 13. Butanol is composed of carbon, hydrogen, and oxygen. If 1.0 mol of butanol contains 6.0 × 10 24 atoms of hydrogen, what is the subscript for the hydrogen atom in C 4 H 2 O? a. 1 b. 10 ____ 14. What is the molar mass of (NH 4 ) 2 CO 3 ? c. d. 6 8 a. 144 g c. b. 138 g d. ____ 15. What is the mass in grams of 5.90 mol C 8 H 18 ? 96 g 78 g a. 0.0512 g b. 19.4 g ____ 16. What is the mass of silver in 3.4 g AgNO 3 ? 389 g 673 g c. d. a. 0.025 g c. 2.2 g b. 0.64 g d. 3.0 g ____ 17. If 60.2 grams of Hg combines completely with 24.0 grams of Br to form a compound, what is the percent composition of Hg in the compound? a. 28.5% c. 71.5% b. 39.9% d. 60.1% ____ 18. What is the percent composition of chromium in BaCrO 4 ? a. 4.87% c. 20.5% b. 9.47% d. 25.2% ____ 19. Which of the following compounds has the lowest percent gold content by weight? a. AuOH c. AuCl 3 b. Au(OH) 3 d. AuI 3 ____ 20. Which of the following is NOT an empirical formula? a. C 2 N 2 H 8 c. BeCr 2 O 7 b. C3 H8 O d. Sb 2 S 3 ____ 21. Which of the following compounds have the same empirical formula? a. CO 2 and SO 2 c. C 4 H 10 and C 10 H 4 b. C 7 H 14 and C 10 H 20 d. C 6 H 12 and C 6 H 14 ____ 22. What is the empirical formula of a compound that is 40% sulfur and 60% oxygen by weight? a. SO c. SO 3 b. SO 2 d. 2 S6 O4 Name: ________________________ ID: A Short Answer 23. A compound has a molecular formula of C6H12O2. What is the empirical formula of this compound? (SHOW YOUR WORK ON YOUR SCANTRON) . 24. A compound has an empirical formula of CH4 but has a molar mass of 32.1 g. What is the molecular formula of this compound? (SHOW YOUR WORK ON YOUR SCANTRON) . 25. What is the empirical formula of a compound that is 53.5% Carbon, 15.5% Hydrogen and 31.1% Nitrogen? You MUST show all your work NEATLY ON YOUR SCANTRON to receive credit. (Partial credit available) 3 ID: A Chapter 10 test Answer Section MATCHING 1. ANS: STO: 2. ANS: STO: 3. ANS: STO: 4. ANS: STO: 5. ANS: STO: 6. ANS: STO: C C.1.14 A C.1.33 B C.1.33 E C.1.31 D C.1.16 F C.1.6 DIF: L1 REF: p. 290 OBJ: 10.1.2 DIF: L1 REF: p. 290 OBJ: 10.1.2 DIF: L1 REF: p. 290 OBJ: 10.2.1 DIF: L1 REF: p. 300 OBJ: 10.2.2 DIF: L1 REF: p. 305 OBJ: 10.3.1 DIF: L1 REF: p. 309 OBJ: 10.3.2 DIF: L1 REF: p. 290 OBJ: 10.1.2 MULTIPLE CHOICE 7. ANS: STO: 8. ANS: OBJ: 9. ANS: STO: 10. ANS: OBJ: 11. ANS: OBJ: 12. ANS: OBJ: 13. ANS: OBJ: 14. ANS: OBJ: 15. ANS: OBJ: 16. ANS: STO: 17. ANS: OBJ: 18. ANS: STO: D C.1.33 C 10.1.2 A C.1.14 B 10.1.2 D 10.1.2 D 10.1.2 B 10.1.2 C 10.1.4 D 10.2.1 C C.1.16 C 10.3.1 C C.1.16 DIF: L1 STO: C.1.17 DIF: L1 DIF: STO: DIF: STO: DIF: STO: DIF: STO: DIF: STO: DIF: STO: DIF: L2 C.1.16 L2 C.1.16 L2 C.1.16 L3 C.1.7 L2 C.1.16 L2 C.1.16 L2 DIF: L2 STO: C.1.16 DIF: L2 REF: p. 291, p. 292 REF: p. 290 OBJ: 10.1.2 REF: p. 290, p. 291 REF: p. 291, p. 292 REF: p. 291, p. 292 REF: p. 290, p. 291 REF: p. 295, p. 296 REF: p. 297, p. 298 REF: p. 298 OBJ: 10.2.1 REF: p. 305, p. 306 REF: p. 307 1 OBJ: 10.3.1 ID: A 19. ANS: STO: 20. ANS: STO: 21. ANS: STO: 22. ANS: STO: D C.1.16 A C.1.6 B C.1.6 C C.1.6 DIF: L3 REF: p. 307 OBJ: 10.3.1 DIF: L1 REF: p. 309 OBJ: 10.3.2 DIF: L1 REF: p. 309 OBJ: 10.3.2 DIF: L2 REF: p. 310 OBJ: 10.3.2 SHORT ANSWER 23. ANS: C3H5O1 24. ANS: C2H8 25. ANS: C9H30N4 2