Question 1

Identify the complete ionic equation for the reaction (if any) that occurs when aqueous solutions of lithium sulfide and copper(II) nitrate are mixed.

Accepted Answer

A)  Li+(aq) + SO42-(aq) + Cu+(aq) + NO3-(aq) → CuS(s) + Li+(aq) + NO3-(aq) 
B)  Li+(aq) + S-(aq) + Cu+(aq) + NO3-(aq) → CuS(s) + LiNO3(aq) 
C)  2Li+(aq) + S2-(aq) + Cu2+(aq) + 2NO3-(aq) → Cu2+(aq) + S2-(aq) + 2LiNO3(s) 
D)  2Li+(aq) + S2-(aq) + Cu2+(aq) + 2NO3-(aq) → CuS(s) + 2Li+(aq) + 2NO3-(aq) 
E)  No reaction occurs. 
A)  Li+(aq) + SO42-(aq) + Cu+(aq) + NO3-(aq) → CuS(s) + Li+(aq) + NO3-(aq) 
B)  Li+(aq) + S-(aq) + Cu+(aq) + NO3-(aq) → CuS(s) + LiNO3(aq) 
C)  2Li+(aq) + S2-(aq) + Cu2+(aq) + 2NO3-(aq) → Cu2+(aq) + S2-(aq) + 2LiNO3(s) 
D)  2Li+(aq) + S2-(aq) + Cu2+(aq) + 2NO3-(aq) → CuS(s) + 2Li+(aq) + 2NO3-(aq) 
E)  No reaction occurs.

Question 2

How many molecules of HCl are formed when 50.0 g of water reacts according to the following balanced reaction? Assume excess 
ICl3. 2ICl3 + 3H2O → ICl + HIO3 + 5HCl

Accepted Answer

A)  2.78 × 1024 molecules HCl 
B)  1.67 × 1024 molecules HCl 
C)  5.02 × 1025 molecules HCl 
D)  6.09 × 1025 molecules HCl 
E)  3.65 × 1024 molecules HCl 
A)  2.78 × 1024 molecules HCl 
B)  1.67 × 1024 molecules HCl 
C)  5.02 × 1025 molecules HCl 
D)  6.09 × 1025 molecules HCl 
E)  3.65 × 1024 molecules HCl

Question 3

Which of the following is a precipitation reaction?

Accepted Answer

A)  2HBr(aq) + NiS(s) →   (aq) +   S(g) 
B)    I(aq) + NaOH(aq) →   O(l) +   (g) + NaI(aq) 
C)  2     (g) + 11   (g) → 8   (g) + 6   O(g) 
D)  4NO(g) + 6   O(g) → 4   (g) +   (g) 
E)    (aq) +     (aq) →   (s) + 2NaBr(aq) 
A)  2HBr(aq) + NiS(s) →   (aq) +   S(g) 
B)    I(aq) + NaOH(aq) →   O(l) +   (g) + NaI(aq) 
C)  2     (g) + 11   (g) → 8   (g) + 6   O(g) 
D)  4NO(g) + 6   O(g) → 4   (g) +   (g) 
E)    (aq) +     (aq) →   (s) + 2NaBr(aq)

Question 4

Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe2O3 react with excess Al according to the following reaction: Fe2O3(s) + 2Al(s) → Al2O3(s) + 2Fe(s)

Accepted Answer

A)  61.03% 
B)  28.65% 
C)  57.30% 
D)  20.02% 
E)  81.93% 
A)  61.03% 
B)  28.65% 
C)  57.30% 
D)  20.02% 
E)  81.93%

Question 5

When dissolved in water, KOH behaves as ________.

Accepted Answer

A)  an acid that forms K+ and OH- ions 
B)  an acid that forms KO- and H+ ions 
C)  a base that forms K+ and OH- ions 
D)  a base that forms KO- and H+ ions 
A)  an acid that forms K+ and OH- ions 
B)  an acid that forms KO- and H+ ions 
C)  a base that forms K+ and OH- ions 
D)  a base that forms KO- and H+ ions

Question 6

What is the reduction half-reaction for the following overall galvanic cell reaction? 
Co2+(aq) + 2Ag(s) → Co(s) + 2 Ag+(aq)

Accepted Answer

A)  Ag(s) + e- → Ag+(aq) 
B)  Ag+(aq) + e- → Ag(s) 
C)  Co2+(aq) + 2 e- → Co(s) 
D)  Co2+(aq) + e- → Co(s) 
A)  Ag(s) + e- → Ag+(aq) 
B)  Ag+(aq) + e- → Ag(s) 
C)  Co2+(aq) + 2 e- → Co(s) 
D)  Co2+(aq) + e- → Co(s)

Question 7

Identify oxidation and reduction half cell reactions:
(a) Zn(s) → Zn2+(aq) + 2e⁻
(b) Cu2+(aq) + 2e⁻ → Cu(s)
Write the name of reaction.

Accepted Answer

Oxidation,

Question 8

What element is undergoing reduction (if any) in the following reaction? 
Zn(s) + 2AgNO3(aq) → Zn(NO3)2(aq) + 2Ag(s)

Accepted Answer

A)  Zn 
B)  N 
C)  O 
D)  Ag 
E)  This is not an oxidation-reduction reaction. 
A)  Zn 
B)  N 
C)  O 
D)  Ag 
E)  This is not an oxidation-reduction reaction.

Question 9

Pure acetic acid (HC2H3O2) is a liquid and is known as glacial acetic acid. Calculate the molarity of a solution prepared by dissolving 50.00 mL of glacial acetic acid at 25 °C in sufficient water to give 500.0 mL of solution. The density of glacial acetic acid at 25 °C is 1.05 g mL-1.

Accepted Answer

A)  6.31 × 103 mol L-1 
B)  105 mol L-1 
C)  0.105 mol L-1 
D)  1.75 × 10-3 mol L-1 
E)  1.75 mol L-1 
A)  6.31 × 103 mol L-1 
B)  105 mol L-1 
C)  0.105 mol L-1 
D)  1.75 × 10-3 mol L-1 
E)  1.75 mol L-1

Question 10

According to the following reaction, how many grams of sulfur are formed when 37.4 g of water are formed? 2H2S(g) + SO2(g) → 3S(s) + 2H2O(l)

Accepted Answer

A)  99.8 g S 
B)  66.6 g S 
C)  56.1 g S 
D)  44.4 g S 
E)  14.0 g S 
A)  99.8 g S 
B)  66.6 g S 
C)  56.1 g S 
D)  44.4 g S 
E)  14.0 g S

Question 11

If the percent yield for the following reaction is 75.0%, and 45.0 g of NO2 are consumed in the reaction, how many grams of nitric acid, HNO3(aq), are produced? 
3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g)

Accepted Answer

A)  30.8 g 
B)  41.1 g 
C)  54.8 g 
D)  69.3 g 
A)  30.8 g 
B)  41.1 g 
C)  54.8 g 
D)  69.3 g

Question 12

Which of the following is an oxidation-reduction reaction?

Accepted Answer

A)  HCl(aq) + LiOH(aq) → LiCl(aq) + H2O(l) 
B)  NaI(aq) + AgNO3(aq) → AgI(s) + NaNO3(aq) 
C)  Pb(C2H3O2)2(aq) + 2NaCl(aq) → PbCl2(s) + 2NaC2H3O2(aq) 
D)  Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) 
E)  All of the above are oxidation-reduction reactions. 
A)  HCl(aq) + LiOH(aq) → LiCl(aq) + H2O(l) 
B)  NaI(aq) + AgNO3(aq) → AgI(s) + NaNO3(aq) 
C)  Pb(C2H3O2)2(aq) + 2NaCl(aq) → PbCl2(s) + 2NaC2H3O2(aq) 
D)  Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) 
E)  All of the above are oxidation-reduction reactions.

Question 13

What is the difference between a voltaic cell and an electrolytic cell?

Accepted Answer

A voltaic cell contains a redox reaction

Question 14

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) +   O(l) →   (s)
A 4.50 g sample of CaO is reacted with 4.34 g of   O. How many grams of water remain after the reaction is complete?

Accepted Answer

A)  0.161 g 
B)  0.00893 g 
C)  1.45 g 
D)  0.241 g 
E)  2.89 g 
A)  0.161 g 
B)  0.00893 g 
C)  1.45 g 
D)  0.241 g 
E)  2.89 g

Question 15

How many grams of calcium chloride are needed to produce 1.50 g of potassium chloride? 
CaCl2(aq) + K2CO3(aq) → 2KCl(aq) + CaCO3(aq)

Accepted Answer

A)  0.896 g 
B)  1.12 g 
C)  2.23 g 
D)  4.47 g 
A)  0.896 g 
B)  1.12 g 
C)  2.23 g 
D)  4.47 g

Question 16

The mixing of which pair of reactants will result in a precipitation reaction?

Accepted Answer

A)  Ba(NO3)2(aq) + Na2CO3(aq) 
B)  K2SO4(aq) + Cu(NO3)2(aq) 
C)  NaClO4(aq) + (NH4)2S(aq) 
D)  NH4Br(aq) + NH4I(aq) 
A)  Ba(NO3)2(aq) + Na2CO3(aq) 
B)  K2SO4(aq) + Cu(NO3)2(aq) 
C)  NaClO4(aq) + (NH4)2S(aq) 
D)  NH4Br(aq) + NH4I(aq)

Question 17

Which one of the following compounds is soluble in water?

Accepted Answer

A)  Cu3(PO4)2 
B)  CoS 
C)  Pb(NO3)2 
D)  ZnCO3 
A)  Cu3(PO4)2 
B)  CoS 
C)  Pb(NO3)2 
D)  ZnCO3

Question 18

How many millilitres of a 9.0 mol L-1 H2SO4 solution are needed to make 0. 35 L of a 3.5 mol L-1 solution?

Accepted Answer

A)  0. 14 mL 
B)  0.90 mL 
C)  140 mL 
D)  900 mL 
A)  0. 14 mL 
B)  0.90 mL 
C)  140 mL 
D)  900 mL

Question 19

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s) +   (g) → 2MgO(s)
How many moles of   are consumed when 0.850 mol of magnesium burns?

Accepted Answer

A)  1.70 
B)  0.850 
C)  0.0350 
D)  0.559 
E)  0.425 
A)  1.70 
B)  0.850 
C)  0.0350 
D)  0.559 
E)  0.425

Question 20

What element is being oxidized in the following (unbalanced) redox reaction? Cr(OH)4⁻(aq) + ClO⁻(aq) → CrO42-(aq) + Cl⁻(aq)

Accepted Answer

A)  Cr 
B)  O 
C)  H 
D)  Cl 
A)  Cr 
B)  O 
C)  H 
D)  Cl

Exam 4: Chemical Reactions and Stoichiometry

Identify the complete ionic equation for the reaction (if any) that occurs when aqueous solutions of lithium sulfide and copper(II) nitrate are mixed.

How many molecules of HCl are formed when 50.0 g of water reacts according to the following balanced reaction? Assume excess ICl3. 2ICl3 + 3H2O → ICl + HIO3 + 5HCl

Which of the following is a precipitation reaction?

Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe2O3 react with excess Al according to the following reaction: Fe2O3(s) + 2Al(s) → Al2O3(s) + 2Fe(s)

When dissolved in water, KOH behaves as ________.

What is the reduction half-reaction for the following overall galvanic cell reaction? Co2+(aq) + 2Ag(s) → Co(s) + 2 Ag+(aq)

Identify oxidation and reduction half cell reactions: (a) Zn(s) → Zn2+(aq) + 2e⁻ (b) Cu2+(aq) + 2e⁻ → Cu(s) Write the name of reaction.

What element is undergoing reduction (if any) in the following reaction? Zn(s) + 2AgNO3(aq) → Zn(NO3)2(aq) + 2Ag(s)

Pure acetic acid (HC2H3O2) is a liquid and is known as glacial acetic acid. Calculate the molarity of a solution prepared by dissolving 50.00 mL of glacial acetic acid at 25 °C in sufficient water to give 500.0 mL of solution. The density of glacial acetic acid at 25 °C is 1.05 g mL-1.

According to the following reaction, how many grams of sulfur are formed when 37.4 g of water are formed? 2H2S(g) + SO2(g) → 3S(s) + 2H2O(l)

If the percent yield for the following reaction is 75.0%, and 45.0 g of NO2 are consumed in the reaction, how many grams of nitric acid, HNO3(aq), are produced? 3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g)

Which of the following is an oxidation-reduction reaction?

What is the difference between a voltaic cell and an electrolytic cell?

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) + O(l) → (s) A 4.50 g sample of CaO is reacted with 4.34 g of O. How many grams of water remain after the reaction is complete?

How many grams of calcium chloride are needed to produce 1.50 g of potassium chloride? CaCl2(aq) + K2CO3(aq) → 2KCl(aq) + CaCO3(aq)

The mixing of which pair of reactants will result in a precipitation reaction?

Which one of the following compounds is soluble in water?

How many millilitres of a 9.0 mol L-1 H2SO4 solution are needed to make 0. 35 L of a 3.5 mol L-1 solution?

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s) + (g) → 2MgO(s) How many moles of are consumed when 0.850 mol of magnesium burns?

What element is being oxidized in the following (unbalanced) redox reaction? Cr(OH)4⁻(aq) + ClO⁻(aq) → CrO42-(aq) + Cl⁻(aq)

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How many molecules of HCl are formed when 50.0 g of water reacts according to the following balanced reaction? Assume excess ICl₃. 2ICl₃ + 3H₂O → ICl + HIO₃ + 5HCl

Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe₂O₃ react with excess Al according to the following reaction: Fe₂O₃(s) + 2Al(s) → Al₂O₃(s) + 2Fe(s)

What is the reduction half-reaction for the following overall galvanic cell reaction? Co²⁺(aq) + 2Ag(s) → Co(s) + 2 Ag⁺(aq)

Identify oxidation and reduction half cell reactions: (a) Zn(s) → Zn²⁺(aq) + 2e⁻ (b) Cu²⁺(aq) + 2e⁻ → Cu(s) Write the name of reaction.

What element is undergoing reduction (if any) in the following reaction? Zn(s) + 2AgNO₃(aq) → Zn(NO₃)₂(aq) + 2Ag(s)

Pure acetic acid (HC₂H₃O₂) is a liquid and is known as glacial acetic acid. Calculate the molarity of a solution prepared by dissolving 50.00 mL of glacial acetic acid at 25 °C in sufficient water to give 500.0 mL of solution. The density of glacial acetic acid at 25 °C is 1.05 g mL^-1.

According to the following reaction, how many grams of sulfur are formed when 37.4 g of water are formed? 2H₂S(g) + SO₂(g) → 3S(s) + 2H₂O(l)

If the percent yield for the following reaction is 75.0%, and 45.0 g of NO₂ are consumed in the reaction, how many grams of nitric acid, HNO₃(aq), are produced? 3NO₂(g) + H₂O(l) → 2HNO₃(aq) + NO(g)

How many grams of calcium chloride are needed to produce 1.50 g of potassium chloride? CaCl₂(aq) + K₂CO₃(aq) → 2KCl(aq) + CaCO₃(aq)

How many millilitres of a 9.0 mol L^-1 H₂SO₄ solution are needed to make 0. 35 L of a 3.5 mol L^-1 solution?

What element is being oxidized in the following (unbalanced) redox reaction? Cr(OH)₄⁻(aq) + ClO⁻(aq) → CrO₄^2-(aq) + Cl⁻(aq)