Unit 4. Multiple Choice Identify the choice that best completes the statement or answers the question.

Transcription

1 Unit 4 Multiple Choice Identify the choice that best completes the statement or answers the question. 39. Changing a subscript in a correctly written chemical formula a. changes the number of moles represented by the formula. b. changes the charges on the other ions in the compound. c. changes the formula so that it no longer represents that compound. d. has no effect on the formula. 40. Which formula does NOT represent a molecule? a. H 2 O (water) c. CO 2 (carbon dioxide) b. NH 3 (ammonia) d. NaCl (table salt) 41. What is the formula for zinc fluoride? a. ZnF c. Zn 2 F b. ZnF 2 d. Zn 2 F What is the formula for the compound formed by calcium ions and chloride ions? a. CaCl c. CaCl 3 b. Ca 2 Cl d. CaCl What is the formula for the compound formed by lead(ii) ions and chromate ions? a. PbCrO 4 c. Pb 2 (CrO 4 ) 3 b. Pb 2 CrO 4 d. Pb(CrO 4 ) What is the formula for aluminum sulfate? a. AlSO 4 c. Al 2 (SO 4 ) 3 b. Al 2 SO 4 d. Al(SO 4 ) What is the formula for tin(iv) chromate? a. Sn(CrO 4 ) 4 c. Sn 2 (CrO 4 ) 4 b. Sn 2 (CrO 4 ) 2 d. Sn(CrO 4 ) Name the compound Fe(NO 2 ) 2. a. iron(ii) nitrate c. ferric nitrate b. iron(ii) nitrite d. ferrous nitride

2 47. Name the compound CuCO 3. a. copper(i) carbonate c. cuprous carbide b. cupric trioxycarbide d. copper(ii) carbonate 48. What is the name of Sn 3 (PO 4 ) 4 under the Stock system of nomenclature? a. stannous phosphate c. tin(iii) phosphate b. tin(iv) phosphate d. tin(ii) phosphate 49. What is the name of Cr 2 (SO 4 ) 3 under the Stock system of nomenclature? a. chromium(ii) sulfate c. chromium(iii) sulfate b. chromic sulfate d. chromous sulfate 50. What is the metallic ion in copper(ii) chloride? a. Co 2+ c. Cu 2+ b. Cl 2 d. Cl 51. Using the Stock system, name the compound PbO. a. plumbous oxide c. potassium oxide b. lead oxide d. lead(ii) oxide 52. Name the compound CF 4. a. calcium fluoride c. carbon tetrafluoride b. carbon fluoride d. monocarbon quadrafluoride 53. What is the formula for silicon dioxide? a. SO 2 c. Si 2 O b. SiO 2 d. S 2 O 54. What is the formula for nitrogen trifluoride? a. NiF 3 c. N 3 F b. NF 3 d. Ni 3 F 55. What is the formula for dinitrogen trioxide? a. Ni 2 O 3 c. N 2 O 6 b. NO 3 d. N 2 O What is the formula for sulfur dichloride? a. NaCl 2 c. S 2 Cl b. SCl 2 d. S 2 Cl 2

3 57. A chemical reaction has NOT occurred if the products have a. the same mass as the reactants. b. less total bond energy than the reactants. c. more total bond energy than the reactants. d. the same chemical properties as the reactants. 58. Which observation does NOT indicate that a chemical reaction has occurred? a. formation of a precipitate c. evolution of heat and light b. production of a gas d. change in total mass of substances 59. In writing an equation that produces hydrogen gas, the correct representation of hydrogen gas is a. H. c. H 2. b. 2H. d. OH. 60. To balance a chemical equation, it may be necessary to adjust the a. coefficients. c. formulas of the products. b. subscripts. d. number of products. 61. A chemical equation is balanced when the a. coefficients of the reactants equal the coefficients of the products. b. same number of each kind of atom appears in the reactants and in the products. c. products and reactants are the same chemicals. d. subscripts of the reactants equal the subscripts of the products. 62. How would oxygen be represented in the formula equation for the reaction of methane and oxygen to yield carbon dioxide and water? a. oxygen c. O 2 b. O d. O When the equation Fe 3 O 4 + Al Al 2 O 3 + Fe is correctly balanced, what is the coefficient of Fe? a. 3 c. 6 b. 4 d Which coefficients correctly balance the formula equation NH 4 NO 2 (s) N 2 (g) + H 2 O(l)? a. 1, 2, 2 c. 2, 1, 1 b. 1, 1, 2 d. 2, 2, Which coefficients correctly balance the formula equation CaO + H 2 O Ca(OH) 2?

4 a. 2, 1, 2 c. 1, 2, 1 b. 1, 2, 3 d. 1, 1, After the first steps in writing an equation, the equation is balanced by a. adjusting subscripts to the formula(s). b. adjusting coefficients to the smallest whole-number ratio. c. changing the products formed. d. making the number of reactants equal to the number of products. 67. What is the balanced equation for the combustion of sulfur? a. S(s) + O 2 (g) SO(g) c. 2S(s) + 3O 2 (g) SO 3 (s) b. S(s) + O 2 (g) SO 2 (g) d. S(s) + 2O 2 (g) SO 4 2 (aq) 68. Which equation is NOT balanced? a. 2H 2 + O 2 2H 2 O b. 4H 2 + 2O 2 4H 2 O c. H 2 + H 2 + O 2 H 2 O + H 2 O d. 2H 2 + O 2 H 2 O 69. In what kind of reaction do two or more substances combine to form a new compound? a. decomposition reaction c. double-replacement reaction b. ionic reaction d. synthesis reaction 70. The equation AX A + X is the general equation for a a. synthesis reaction. c. combustion reaction. b. decomposition reaction. d. single-replacement reaction. 71. In what kind of reaction does one element replace a similar element in a compound? a. single-replacement reaction c. decomposition reaction b. double-replacement reaction d. ionic reaction 72. The equation AX + BY AY + BX is the general equation for a a. synthesis reaction. c. single-replacement reaction. b. decomposition reaction. d. double-replacement reaction. 73. The equation A + X AX is the general equation for a(n) a. combustion reaction. c. synthesis reaction. b. ionic reaction. d. double-replacement reaction.

5 74. In what kind of reaction does a single compound produce two or more simpler substances? a. decomposition reaction c. single-replacement reaction b. synthesis reaction d. ionic reaction 75. The equation A + BX AX + B is the general equation for a a. double-replacement reaction. c. single-replacement reaction. b. decomposition reaction. d. combustion reaction. 76. In what kind of reaction do the ions of two compounds exchange places in aqueous solution to form two new compounds? a. synthesis reaction c. decomposition reaction b. double-replacement reaction d. combustion reaction 77. The reaction 2Mg(s) + O 2 (g) 2MgO(s) is a a. synthesis reaction. c. single-replacement reaction. b. decomposition reaction. d. double-replacement reaction. 78. The reaction Mg(s) + 2HCl(aq) H 2 (g) + MgCl 2 (aq) is a a. composition reaction. c. single-replacement reaction. b. decomposition reaction. d. double-replacement reaction. 79. The reaction 2HgO(s) 2Hg(l) + O 2 (g) is a(n) a. single-replacement reaction. c. ionic reaction. b. synthesis reaction. d. decomposition reaction. 80. The reaction Pb(NO 3 ) 2 (aq) + 2KI(aq) PbI 2 (s) + 2KNO 3 (aq) is a a. double-replacement reaction. c. decomposition reaction. b. synthesis reaction. d. combustion reaction. 81. What is the balanced equation when aluminum reacts with copper(ii) sulfate? a. Al + Cu 2 S Al 2 S + Cu c. Al + CuSO 4 AlSO 4 + Cu b. 2Al + 3CuSO 4 Al 2 (SO 4 ) 3 + 3Cu d. 2Al + Cu 2 SO 4 Al 2 SO 4 + 2Cu 82. What is the name of a list of elements arranged according to the ease with which they undergo certain chemical reactions? a. reactivity list c. activity series b. reaction sequence d. periodic list 83. An element in the activity series can replace any element

6 a. in the periodic table. c. above it on the list. b. below it on the list. d. in its group. 84. Predict what happens when nickel is added to a solution of potassium chloride. a. No reaction occurs. c. Potassium nickel chloride forms. b. Nickel chloride forms. d. Hydrochloric acid forms. 85. Magnesium bromide + chlorine yield a. Mg and BrCl. c. MgBrCl. b. MgCl and Br 2. d. Mg(Cl) 2 and Br Which reaction does NOT occur? a. 2HF + Cl 2 F 2 + 2HCl c. Fe + CuCl 2 FeCl 2 + Cu b. 2Na + ZnF 2 2NaF + Zn d. 2HCl + Mg MgCl 2 + H Which reaction can be predicted from the activity series? a. 2Cl Cl 2 c. 2HCl + 2Na 2NaCl + H 2 b. HCl + NaOH NaCl + H 2 O d. Cl 2 2Cl 95. When iron ore is processed to obtain iron, the reaction occurs as: Fe 2 O 3 (s) + CO(g) Fe(l) + CO 2 (g) Which of the following is a balanced equation for this reaction? a. Fe 2 O 3 (s) + CO(g) Fe(l) + CO 2 (g) b. Fe 2 O 3 (s) + 3 CO(g) 2 Fe(l) + 2 CO 2 (g) c. Fe 2 O 3 (s) + 2 CO(g) Fe(l) + 2 CO 2 (g) d. Fe 2 O 3 (s) + 3 CO(g) 2 Fe(l) + 3 CO 2 (g) 98. Given the balanced equation representing a reaction: 4Al(s) + 3O2(g) 2Al2O3(s) Which type of chemical reaction is represented by this equation? (1) double replacement (2) single replacement (3) substitution (4) synthesis

7 99. Why can an increase in temperature lead to more effective collisions between reactant particles and an increase in the rate of a chemical reaction? (1) The activation energy of the reaction increases. (2) The activation energy of the reaction decreases. (3) The number of molecules with sufficient energy to react increases. (4) The number of molecules with sufficient energy to react decreases. 1.A chemical formula for a molecular compound represents the composition of a. a molecule. c. the ions that make up the compound. b. an atom. d. the crystal lattice. 2. What is the formula for the compound formed by calcium ions and chloride ions? a. CaCl c. CaCl 3 b. Ca 2 Cl d. CaCl 2 3. What is the formula for barium hydroxide? a. BaOH c. Ba(OH) 2 b. BaOH 2 d. Ba(OH) 4. Name the compound KClO 3. a. potassium chloride c. potassium chlorate b. potassium trioxychlorite d. hypochlorite 5. Name the compound Fe(NO 2 ) 2. a. iron(ii) nitrate c. ferric nitrate

8 b. iron(ii) nitrite d. ferrous nitride 6. What is the metallic ion in copper(ii) chloride? a. Co 2+ c. Cu 2+ b. Cl 2 d. Cl 7. Name the compound CF 4. a. calcium fluoride c. carbon tetrafluoride b. carbon fluoride d. monocarbon quadrafluoride 8. Name the compound SO 3. a. sulfur trioxide c. selenium trioxide b. silver trioxide d. sodium trioxide 9. Name the compound N 2 O 3. a. dinitrogen oxide c. nitric oxide b. nitrogen trioxide d. dinitrogen trioxide 10. What is the formula for silicon dioxide? a. SO 2 c. Si 2 O b. SiO 2 d. S 2 O

9 11. What is the formula for carbon disulfide? a. CaS 2 c. S 2 C b. CS 2 d. SC What is the sum of the atomic masses of all the atoms in a formula for a compound? a. molecular mass c. atomic mass b. formula mass d. actual mass 13. What is the formula mass of ethyl alcohol, C 2 H 5 OH? a amu c amu b amu d amu 14. The molar mass of CCl 4 is g/mol. How many grams of CCl 4 are needed to have mol? a. 5 g c g b g d g 15. The molar mass of CS 2 is g/mol. How many grams of CS 2 are present in mol? a g c g b g d g 16. How many OH ions are present in 3.00 mol of Ca(OH) 2?

10 a c b d How many Mg 2+ ions are found in 1.00 mol of MgO? a c b d If mol of Na + combines with mol of Cl to form NaCl, how many formula units of NaCl are present? a c b d What is the percentage composition of chlorine in NaCl? a % c. 60.7% b. 50% d. 64.5% 20. What is the percentage composition of oxygen in H 2 O? a % c. 88.8% b. 33% d. 99.8% 21. The empirical formula for a compound shows the symbols of the elements with subscripts indicating the a. actual numbers of atoms in a molecule.

11 b. number of moles of the compound in 100 g. c. smallest whole-number ratio of the atoms. d. atomic masses of each element. 22. The empirical formula may not represent the actual composition of a unit of a(n) a. ionic compound. c. atom. b. molecular compound. d. crystal. 23. What is the empirical formula for a compound that is 53.3% O and 46.7% Si? a. SiO c. Si 2 O b. SiO 2 d. Si 2 O What is the empirical formula for a compound that is 36.1% Ca and 63.9% Cl? a. CaCl c. CaCl 2 b. Ca 2 Cl d. Ca 2 Cl A compound contains 27.3 g of C and 72.7 g of O. What is the empirical formula for this compound? a. CO c. C 2 O b. CO 2 d. C 2 O 4 Standard Chemistry do not study The empirical formula and the formula mass of a compound are needed to determine the compound's

12 a. molecular formula. c. lattice structure. b. bond energy. d. toxicity. 27. Of the following molecular formulas for hydrocarbons, which is an empirical formula? a. CH 4 c. C 3 H 6 b. C 2 H 2 d. C 4 H A compound's empirical formula is C 2 H 5. If the formula mass is 58 amu, what is the molecular formula? a. C 3 H 6 c. C 5 H 8 b. C 4 H 10 d. C 5 H A compound's empirical formula is CH. If the formula mass is 26 amu, what is the molecular formula? a. C 2 H 2 c. CH 4 b. CH 3 d. C 4 H 30. A compound's empirical formula is HO. If the formula mass is 34 amu, what is the molecular formula? a. H 2 O c. HO 3 b. H 2 O 2 d. H 2 O 3 Short Answer 31. Explain the term empirical formula. What is the empirical formula of strontium bromide, SrBr 2?

13 Problem 32. The molar mass of aluminum is g/mol and the molar mass of fluorine is g/mol. Calculate the molar mass of aluminum trifluoride, AlF The molar mass of copper is g/mol, the molar mass of sulfur is g/mol, and the molar mass of oxygen is g/mol. Calculate the molar mass of copper(ii) sulfate, CuSO The molar mass of iron is g/mol, the molar mass of silicon is g/mol, and the molar mass of oxygen is g/mol. Calculate the molar mass of iron(ii) silicate, Fe 2 SiO The molar mass of aluminum is g/mol and the molar mass of oxygen is g/mol. Determine the molar mass of Al 2 O 3.