Exam #3
47) Define an Arrhenius base.
E) produces OH- ions in aqueous solution
52) Determine the oxidation state of P in PO3^3-.
A) +3
85) How many grams of CaCl2 are formed when 30.00 mL of 0.00237 M Ca(OH)2 reacts with excess Cl2 gas? 2 Ca(OH)2(aq) + 2 Cl2(g) → Ca(OCl)2(aq) + CaCl2(s) + 2 H2O(l)
A) 0.00395 g
48) The titration of 25.0 mL of an unknown concentration H2SO4 solution requires 83.6 mL of 0.12 M LiOH solution. What is the concentration of the H2SO4 solution (in M)?
A) 0.20 M
14) How many moles of nitrogen are formed when 58.6 g of KNO3 decomposes according to the following reaction? The molar mass of KNO3 is 101.11 g/mol. 4 KNO3(s) → 2 K2O(s) + 2 N2(g) + 5 O2(g)
A) 0.290 mol N2
86) When 15.6 mL of 0.500 M AgNO3 is added to 12.5 mL of 0.300 M NH4Cl, how many grams of AgCl are formed? AgNO3(aq) + NH4Cl(aq) → AgCl(s) + NH4NO3(aq)
A) 0.537 g
33) What mass (in g) of AgCl is formed from the reaction of 75.0 mL of a 0.078 M AgC2H3O2solution with 55.0 mL of 0.109 M MgCl2 solution? 2 AgC2H3O2(aq) + MgCl2(aq) → 2 AgCl(s) + Mg(C2H3O2)2(aq)
A) 0.838 g
6) Determine the mass percent (to the hundredths place) of H in sodium bicarbonate (NaHCO3).
A) 1.20
24) Determine the molarity of a solution formed by dissolving 4.00 moles of KBr in enough water to yield 3.00 L of solution.
A) 1.33 M
2) How many moles of NF3 contain 2.55 × 1024 fluorine atoms?
A) 1.41 moles NF3
25) Determine the molarity of a solution formed by dissolving 97.7 g LiBr in enough water to yield 750.0 mL of solution.
A) 1.50 M
79) What is the concentration (M) of CH3OH in a solution prepared by dissolving 12.5 g of CH3OH in sufficient water to give exactly 230 mL of solution?
A) 1.70 M
87) When 8.00 × 1022 molecules of ammonia react with 7.00 × 1022 molecules of oxygen according to the chemical equation shown below, how many grams of nitrogen gas are produced? 4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g)
A) 1.86 g Diff: 5 Var: 5 LO: 4.2 Global: G4
80) How many grams of H3PO4 are in 255 mL of a 4.50 M solution of H3PO4?
A) 112 g
75) Sodium metal and water react to form hydrogen and sodium hydroxide. If 17.94 g of sodium react with water to form 0.78 g of hydrogen and 31.20 g of sodium hydroxide, what mass of water was involved in the reaction?
A) 14.04 g
44) Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of MgSO3 and HI are mixed. A) 2 H+(aq) + SO32-(aq) → H2O(l) + SO2(g) B) Mg2+(aq) + 2 I-(aq) → MgI2(s) C) 2 H+(aq) + SO32-(aq) + Mg2+(aq) + 2 I-(aq) → H2SO3(s) + MgI2(aq) D) 2 H+(aq) + SO32-(aq) + Mg2+(aq) + 2 I-(aq) → H2O(l) + SO2(g) + Mg2+(aq) + 2 I-(aq) E) No reaction occurs.
A) 2 H+(aq) + SO32-(aq) → H2O(l) + SO2(g)
83) How many grams of C OH must be added to water to prepare 325 mL of a solution that is 4.50 M CH3OH?
A) 47.0 g
78) What is the concentration (M) of sodium ions in 4.57 L of a 2.35 M Li3P solution?
A) 7.05 M
1) Give the mass percent of carbon in C14H19NO2.
A) 72.07%
88) When silver nitrate reacts with barium chloride, silver chloride and barium nitrate are formed. How many grams of silver chloride are formed when 10.2 g of silver nitrate reacts with 15.0 g of barium chloride?
A) 8.61 g
16) According to the following reaction, how many grams of sulfur are formed when 37.4 g of water are formed? 2 H2S(g) + SO2(g) → 3 S(s) + 2 H2O(l)
A) 99.8 g S
35) Choose the statement below that is TRUE. A) A weak acid solution consists of mostly nonionized acid molecules .B) The term "strong electrolyte" means that the substance is extremely reactive. C) A strong acid solution consists of only partially ionized acid molecules .D) The term "weak electrolyte" means that the substance is inert. E) A molecular compound that does not ionize in solution is considered a strong electrolyte.
A) A weak acid solution consists of mostly nonionized acid molecules.
57) Determine the oxidizing agent in the following reaction. Ni(s) + 2 AgClO4(aq) → Ni(ClO4)2(aq) + 2 Ag(s)
A) Ag
59) Identify the oxidizing agent. 2 Al3+(aq) + 2 Fe(s) → 2 Al(s) + 3 Fe2+(aq)
A) Al3+
60) Identify the species reduced. 2 Al3+(aq) + 2 Fe(s) → 2 Al(s) + 3 Fe2+(aq)
A) Al3+
9) A certain alcohol contains only three elements, carbon, hydrogen, and oxygen. Combustion of a 20.00 gram sample of the alcohol produced 38.20 grams of CO2 and 23.48 grams of H2O. What is the empirical formula of the alcohol?
A) C2H6O
50) Choose the reaction that represents the combustion of C6H12O2.
A) C6H12O2(l) + 8 O2(g) → 6 CO2(g) + 6 H2O(g)
41) Give the spectator ions for the reaction that occurs when aqueous solutions of K2S and Fe(NO3)2 are mixed. A) K+ and NO3- D) Fe2+ and S2- B) Fe2+ and K+ E) No spectator ions are present. C) S2- and NO3-
A) K+ and NO3-
55) What element is undergoing oxidation (if any) in the following reaction? Zn(s) + 2 AgNO3(aq) → Zn(NO3)2(aq) + 2 Ag(s)
A) Zn
26) Determine the molarity of a solution formed by dissolving 468 mg of MgI2 in enough water to yield 50.0 mL of solution.
B) 0.0337 M
77) What volume of a 0.540 M NaOH solution contains 12.5 g of NaOH?
B) 0.579 L
65) Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6 Li(s) + (g) → 2 Li3N(s) How many moles of lithium are needed to produce 0.31 mol of N when the reaction is carried out in the presence of excess nitrogen?
B) 0.93
27) How many molecules of sucrose (C12H22O11, molar mass = 342.30 g/mol) are contained in 14.3 mL of 0.140 M sucrose solution?
B) 1.21 × 1021 molecules C12H22O11
82) How many grams of NaOH (MW = 40.0) are in 150.0 mL of a 0.300 M NaOH solution?
B) 1.80 g
72) The density of ethanol, C2H5OH, is 0.789 g/mL. How many milliliters of ethanol are needed to produce 30.0 g of CO2 according to the following chemical equation? C2H5OH(l) + 3 O2(g) → 2 CO2(g) + 3 H2O(l)
B) 19.9 mL
11) Aluminum metal reacts with aqueous cobalt(II) nitrate to form aqueous aluminum nitrate and cobalt metal. What is the stoichiometric coefficient for aluminum when the chemical equation is balanced using the lowest, whole-number stoichiometric coefficients?
B) 2
69) Balance the chemical equation given below, and determine the number of moles of iodine that react with 40.0 g of aluminum. _____ Al(s) + _____ I2(s) → _____ Al2I6(s)
B) 2.22 mol
3) How many moles of PF3 contain 3.68 × 1025 fluorine atoms?
B) 20.4 moles PF3
30) According to the following reaction, what mass of PbCl2 can form from 235 mL of 0.110 M KCl solution? Assume that there is excess Pb(NO3)2. 2 KCl(aq) + Pb(NO3)2(aq) → PbCl2(s) + 2 KNO3(aq)
B) 3.59 g
71) Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas. How many grams of oxygen are formed when 10.0 g of dinitrogen monoxide decomposes?
B) 3.64 g
68) How many grams of calcium chloride are needed to produce 5.00 g of potassium chloride? CaCl2(aq) + K2CO3(aq) → 2 KCl(aq) + CaCO3(aq)
B) 3.72 g
84) What is the concentration of HCl in the final solution when 65 mL of a 9.0 M HCl solution is diluted with pure water to a total volume of 0.15 L?
B) 3.9 M
18) A 12.39 g sample of phosphorus reacts with 42.54 g of chlorine to form only phosphorus trichloride (PCl3). If it is the only product, what mass of PCl3 is formed?
B) 54.93 g
5) A sample of pure lithium nitrate contains 7.99% lithium by mass. What is the % lithium by mass in a sample of pure lithium nitrate that has twice the mass of the first sample?
B) 7.99%
17) How many molecules of H2S are required to form 79.0 g of sulfur according to the following reaction? Assume excess SO2. 2 H2S(g) + SO2(g) → 3 S(s) + 2 H2O(l)
B) 9.89 × 1023 molecules H2S
58) Identify the reducing agent. 2 Al3+(aq) + 2 Fe(s) → 2 Al(s) + 3 Fe2+(aq)
B) Fe
61) Identify the species oxidized. 2 Al3+(aq) + 2 Fe(s) → 2 Al(s) + 3 Fe2+(aq)
B) Fe
40) Give the complete ionic equation for the reaction (if any) that occurs when aqueous solutions of K2S and Fe(NO3)2 are mixed. A) K+(aq) + NO3-(aq) → KNO3(s) B) Fe2+(aq) + S2-(aq) + 2 K+(aq) + 2 NO3-(aq) → FeS(s) + 2 K+(aq) + 2 NO3-(aq) C) Fe2+(aq) + S2-(aq) + 2 K+(aq) + 2 NO3-(aq) → Fe2+(aq) + S2-(aq) + 2 KNO3(s) D) Fe2+(aq) + S2-(aq) → FeS(s) E) No reaction occurs.
B) Fe2+(aq) + S2-(aq) + 2 K+(aq) + 2 NO3-(aq) → FeS(s) + 2 K+(aq) + 2 NO3-(aq)
45) Give the spectator ions for the reaction that occurs when aqueous solutions of MgSO3 and HI are mixed. A) H+ and SO32- D) SO32- and Mg2+ B) Mg2+ and I- E) No spectator ions are present. C) H+ and I-
B) Mg2+ and I-
37) Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of lithium sulfide and copper(II) nitrate are mixed. A) Li+(aq) + NO3-(aq) → LiNO3(s) B) S2-(aq) + Cu2+(aq) → CuS(s) C) 2 Li+(aq) + S2-(aq) + Cu2+(aq) + 2 NO3-(aq) → Cu2+(aq) + S2-(aq) + 2 LiNO3(s) D) 2 Li+(aq) + S2-(aq) + Cu2+(aq) + 2 NO3-(aq) → CuS(s) + 2 Li+(aq) + 2 NO3-(aq) E) No reaction occurs.
B) S2-(aq) + Cu2+(aq) → CuS(s)
49) The titration of 80.0 mL of an unknown concentration H3PO4 solution requires 126 mL of 0.218 M KOH solution. What is the concentration of the H3PO4 solution (in M)?
C) 0.114 M
23) Determine the molarity of a solution formed by dissolving 3.00 moles of NaCl in enough water to yield 4.00 L of solution.
C) 0.750 M
81) What is the concentration (M) of a NaCl solution prepared by dissolving 5.3 g of NaCl in sufficient water to give 115 mL of solution?
C) 0.79 M
4) How many moles of C5H8 contain 4.95 × 1024 hydrogen atoms?
C) 1.03 moles C5H8
28) According to the following reaction, how many moles of Fe(OH)2 can form from 175.0 mL of 0.227 M LiOH solution? Assume that there is excess FeCl2. FeCl2(aq) + 2 LiOH(aq) → Fe(OH)2(s) + 2 LiCl(aq)
C) 1.99 × 10-2 moles
66) Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2 NaN3(s) → 2 Na(s) + 3 N2(g) How many moles of N2 are produced by the decomposition of 1.75 mol of sodium azide?
C) 2.63
12) Radium phosphate reacts with sulfuric acid to form radium sulfate and phosphoric acid. What is the coefficient for sulfuric acid when the equation is balanced using the lowest, whole- numbered coefficients?
C) 3
53) What element is undergoing oxidation (if any) in the following reaction? CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g)
C) C
19) Determine the limiting reactant (LR) and the mass (in g) of nitrogen that can be formed from 50.0 g N2O4 and 45.0 g N2H4. Some possibly useful molar masses are as follows: N2O4 = 92.02 g/mol, N2H4 = 32.05 g/mol. N2O4(l) + 2 N2H4(l) → 3 N2(g) + 4 H2O(g)
C) LR = N2O4, 45.7 g N2 formed
38) Identify the spectator ions for the reaction that occurs when aqueous solutions of lithium sulfide and copper(II) nitrate are mixed. A) Cu2+ and NO3- B) Li+ and Cu2+ C) Li+ and NO3- D) S2- and Cu2+ E) No spectator ions are present.
C) Li+ and NO3-
76) Which substance is the limiting reactant when 12 g of sulfur reacts with 18 g of oxygen and 24 g of sodium hydroxide according to the following chemical equation? 2 S(s) + 3 O2(g) + 4 NaOH(aq) → 2 Na2SO4(aq) + 2 H2O(l)
C) NaOH(aq)
62) Global warming is thought to be caused by the increase of one particular gas. Name the gas.
C) carbon dioxide
46) Define an Arrhenius acid.
C) produces H+ ions in aqueous solution
31) Determine the number of grams H2 formed when 250.0 mL of 0.743 M HCl solution reacts with 3.41 × 1023 atoms of Fe according to the following reaction. 2 HCl(aq) + Fe(s) → H2(g) + FeCl2(aq)
D) 0.187 g
15) Two samples of calcium fluoride are decomposed into their constituent elements. The first sample produced 0.154 g of calcium and 0.146 g of fluorine. If the second sample produced 294 mg of fluorine, how many g of calcium were formed?
D) 0.309 g
13) How many moles of oxygen are formed when 58.6 g of KNO3 decomposes according to the following reaction? The molar mass of KNO3 is 101.11 g/mol. 4 KNO3(s) → 2 K2O(s) + 2 N2(g) + 5 O2(g)
D) 0.724 mol O2
8) How many chloride ions are there in 7.50 mol of aluminum chloride?
D) 1.35 × 1025 chloride ions
64) According to the following balanced reaction, how many moles of HNO3 are formed from 2.50 moles of NO2 if there is plenty of water present? 3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)
D) 1.67 moles NO
70) Balance the chemical equation given below, and determine the number of grams of MgO that are needed to produce 20.0 g of Fe2O3. _____ MgO(s) + _____ Fe(s) → _____ Fe2O3(s) + _____ Mg(s)
D) 15.1 g
43) Give the complete ionic equation for the reaction (if any) that occurs when aqueous solutions of MgSO3 and HI are mixed. A) 2 H+(aq) + SO32-(aq) → H2O(l) + SO2(g) B) Mg2+(aq) + 2 I-(aq) → MgI2(s) C) 2 H+(aq) + SO32-(aq) + Mg2+(aq) + 2 I-(aq) → H2SO3(s) + MgI2(aq) D) 2 H+(aq) + SO32-(aq) + Mg2+(aq) + 2 I-(aq) → H2O(l) + SO2(g) + Mg2+(aq) + 2 I-(aq) E) No reaction occurs.
D) 2 H+(aq) + SO32-(aq) + Mg2+(aq) + 2 I-(aq) → H2O(l) + SO2(g) + Mg2+(aq) + 2 I-(aq)
36)Give the complete ionic equation for the reaction (if any) that occurs when aqueous solutions of lithium sulfide and copper(II) nitrate are mixed. A) 2 Li+(aq) + S2-(aq) + Cu2+(aq) + 2 NO3-(aq) → Cu2+(aq) + S2-(aq) + 2 Li+(aq) + 2 NO3-(aq) B) 2 Li+(aq) + S2-(aq) + Cu2+(aq) + 2 NO3-(aq) → CuS(s) + 2 LiNO3(s) C) 2 Li+(aq) + S2-(aq) + Cu2+(aq) + 2 NO3-(aq) → Cu2+(aq) + S2-(aq) + 2 LiNO3(s) D) 2 Li+(aq) + S2-(aq) + Cu2+(aq) + 2 NO3-(aq) → CuS(s) + 2 Li+(aq) + 2 NO3-(aq) E) No reaction occurs.
D) 2 Li+(aq) + S2-(aq) + Cu2+(aq) + 2 NO3-(aq) → CuS(s) + 2 Li+(aq) + 2 NO3-(aq)
10) What is the stoichiometric coefficient for oxygen when the following equation is balanced using the lowest, whole-number coefficients? _____ C H4O (l) + _____ O2(g) → _____ CO2(g) + _____ H2O(l)
D) 3
73) Consider the following reaction. How many moles of oxygen are required to produce 2.00 moles of carbon dioxide? Assume that there is excess C3H7SH present. C3H7SH(l) + 6 O2(g) → 3 CO2(g) + SO2(g) + 4 H2O(g)
D) 4.00 moles O2
20) Determine the theoretical yield of HCl if 60.0 g of BCl3 and 37.5 g of H2O are reacted according to the following balanced reaction. A possibly useful molar mass is BCl3 = 117.16 g/mol. BCl3(g) + 3 H2O(l) → H3BO3(s) + 3 HCl(g)
D) 56.0 g HCl
7) How many oxygen atoms are there in 5.00 g of sodium dichromate, Na2Cr2O7?
D) 8.04 × 1022 oxygen atoms
74) Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) + H2O(l) → Ca(OH)2(s) In a particular experiment, a 2.50-g sample of CaO is reacted with excess water and 2.80 g of Ca(OH)2 is recovered. What is the percent yield in this experiment?
D) 84.9
29) According to the following reaction, what volume of 0.244 M KCl solution is required to react exactly with 50.0 mL of 0.210 M Pb(NO3)2 solution? 2 KCl(aq) + Pb(NO3)2(aq) → PbCl2(s) + 2 KNO3(aq)
D) 86.1 mL
54) What element is undergoing reduction (if any) in the following reaction? Zn(s) + 2 AgNO3(aq) → Zn(NO3)2(aq) + 2 Ag(s)
D) Ag
39) Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of K2S and Fe(NO3)2 are mixed. A) K+(aq) + NO3-(aq) → KNO3(s) B) Fe2+(aq) + S2-(aq) + 2 K+(aq) + 2 NO3-(aq) → FeS(s) + 2 K+(aq) + 2 NO3-(aq) C) Fe2+(aq) + S2-(aq) + 2 K+(aq) + 2 NO3-(aq) → Fe2+(aq) + S2-(aq) + 2 KNO3(s) D) Fe2+(aq) + S2-(aq) → FeS(s) E) No reaction occurs.
D) Fe2+(aq) + S2-(aq) → FeS(s)
42) Give the spectator ions for the reaction that occurs when aqueous solutions of Na2CO3 and HCl are mixed. A) H+ and CO32- D) Na+ and Cl- B) Na+ and CO32- E) No spectator ions are present. C) H+ and Cl-
D) Na+ and Cl-
34) Identify ammonia. A) strong electrolyte, strong base B) strong electrolyte, weak base C) weak electrolyte, strong base D) weak electrolyte, weak base E) nonelectrolyte
D) weak electrolyte, weak base
67) Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2 Mg(s) + O2(g) → 2 MgO(s) How many moles of O2 are consumed when 2.10 mol of magnesium burns?
E) 1.05
21) According to the following reaction, what amount of Al2S3 remains when 20.00 g of Al2S3and 2.00 g of H2O are reacted? A few of the molar masses are as follows: Al2S3 = 150.17 g/mol, H2O = 18.02 g/mol. Al2S3(s) + 6 H2O(l) → 2 Al(OH)3(s) + 3 H2S(g)
E) 17.22 g
32) What volume of 0.305 M AgNO3 is required to react exactly with 155.0 mL of 0.274 M Na2SO4 solution? Hint: You will want to write a balanced reaction.
E) 278 mL
63) According to the following balanced reaction, how many moles of NO are formed from 12.66 moles of NO2 if there is plenty of water present? 3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)
E) 4.22 moles NO
22) Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe2O3react with excess Al according to the following reaction. Fe2O3(s) + 2 Al(s) → Al2O3(s) + 2 Fe(s)
E) 81.93%
51) Identify the combustion reaction. A) 2 C3H7OH(l) + 9 O2(g) → 6 CO2(g) + 8 H2O(g) B) 2 H2(g) + O2(g) → 2 H2O(g) C) C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O D) C(s) + O2(g) → CO2(g) E) All of the reactions are examples of combustion reactions.
E) All of the reactions are examples of combustion reactions.
56) Determine the reducing agent in the following reaction. 2 Li(s) + Fe(C2H3O2)2(aq) → 2 LiC2H3O2(aq) + Fe(s)
E) Li
