Question 1

Which one of the following is the best electrolyte?

Accepted Answer

A)  C12H22O11(aq) 
B)  NaCl(aq) 
C)  AgCl(aq) 
D)  CaSO4(aq) 
E)  CH3COOH(aq)

Question 2

How many millilitres of 0.260 mol L-1 Na2S are needed to react with 40.00 mL of 0.315 mol L-1 AgNO3? Na2S(aq) + 2AgNO3(aq) → 2NaNO3(aq) + Ag2S(s)

Accepted Answer

A)  24.2 mL 
B)  48.5 mL 
C)  66.0 mL 
D)  96.9 mL

Question 3

Identify the location of oxidation in an electrochemical cell.

Accepted Answer

A)  the anode 
B)  the cathode 
C)  the electrode 
D)  the salt bridge 
E)  the socket

Question 4

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of ClO2 and H2O in the balanced reaction? 
H2O2(l) + ClO2(aq) → ClO2⁻(aq) + O2(g)

Accepted Answer

A)  ClO2 = 1, H2O = 1 
B)  ClO2 = 1, H2O = 2 
C)  ClO2 = 4, H2O = 3 
D)  ClO2 = 4, H2O = 2 
E)  ClO2 = 2, H2O = 2

Question 5

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Br2 and OH⁻ in the balanced reaction? 
Br2(l) → BrO3⁻(aq) + Br⁻(aq)

Accepted Answer

A)  Br2 = 1, OH⁻ = 2 
B)  Br2 = 2, OH⁻ = 5 
C)  Br2 = 3, OH⁻ = 3 
D)  Br2 = 3, OH⁻ = 6 
E)  Br2 = 1, OH⁻ = 6

Question 6

A stock solution of HNO3 is prepared and found to contain 13.7 mol L-1 of  . If 25.0 mL of the stock solution is diluted to a final volume of 0.500 L, what is the concentration of the diluted solution?

Accepted Answer

A)  1.46 mol L-1 
B)  274 mol L-1 
C)  0.274 mol L-1 
D)  685 mol L-1 
E)  0.685 mol L-1

Question 7

How many millilitres of 0.152 mol L-1  solution are needed to neutralize 50.00 mL of 0.0793 mol L-1 NaOH?

Accepted Answer

A)  0.0383 
B)  0.104 
C)  0.603 
D)  95.8 
E)  26.1

Question 8

Calculate the number of grams of solute in 500.0 mL of 0.189 mol L-1 KOH.

Accepted Answer

A)  5.30 g 
B)  5.30 × 103 g 
C)  1.68 g 
D)  1.68 × 10-3 g 
E)  21.2 g

Question 9

Determine the oxidation state of S in MgSO4.

Accepted Answer

A)  -4 
B)  +2 
C)  +4 
D)  +6 
E)  -2

Question 10

Match the following.
-H2SO4(aq) + 2LiOH(aq) → 2H2O(l) + Li2SO4(aq)

Accepted Answer

A) acid-base 
B) oxidation-reduction 
C) precipitation 
D) gas evolution 
E) combustion

Question 11

Carbonic acid can form water and carbon dioxide upon heating. How much carbon dioxide is formed from 6.20 g of carbonic acid? H2CO3 → H2O + CO2

Accepted Answer

A)  4.40 g 
B)  8.80 g 
C)  2.20 g 
D)  6.20 g

Question 12

Calculate the concentration (molarity) of a solution prepared by dissolving 72.8 g C2H6O in 2.34 L of water.

Accepted Answer

A)  1.58 M 
B)  1.48 M 
C)  0.987 M 
D)  0.633 M 
E)  0.675 M

Question 13

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Cd and Ag+ in the balanced reaction? 
Cd(s) + Ag+(aq) → Ag(s) + Cd2+(aq)

Accepted Answer

A)  Cd = 1, Ag⁺ = 2 
B)  Cd = 1, Ag⁺ = 1 
C)  Cd = 2, Ag⁺ = 1 
D)  Cd = 2, Ag⁺ = 2 
E)  Cd = 3, Ag⁺ = 1

Question 14

Match the following.
-2HCl(aq) + (NH4)2S(aq) → H2S(g) + 2NH4Cl(aq)

Accepted Answer

A) acid-base 
B) oxidation-reduction 
C) precipitation 
D) gas evolution 
E) combustion

Question 15

How many molecules of H2S are required to form 79.0 g of sulfur according to the following reaction? Assume excess 
SO2. 2H2S(g) + SO2(g) → 3S(s) + 2H2O(l)

Accepted Answer

A)  1.48 × 1024 molecules H2S 
B)  9.89 × 1023 molecules H2S 
C)  5.06 × 1025 molecules H2S 
D)  3.17 × 1025 molecules H2S 
E)  2.44 × 1023 molecules H2S

Question 16

How many moles of Co²⁺ are present in 0.150 L of a 0.200 mol L^-1 solution of CoI₂ ?

Accepted Answer

The answer of How many moles of Co²⁺ are present...

Question 17

What volume of 0.305 mol L-1 AgNO3 is required to react exactly with 155.0 mL of 0.274 mol L-1 Na2SO4 solution? Hint: You will want to write a balanced reaction.

Accepted Answer

A)  581 mL 
B)  173 mL 
C)  345 mL 
D)  139 mL 
E)  278 mL

Question 18

Which of the following statements is FALSE?

Accepted Answer

A)  The limiting reactant is the one that is available in the smallest stochiometric quantity. 
B)  The amount of product that can be made from the excess reactant is the theoretical yield. 
C)  Coefficients in chemical equations are used as conversion factors between the amounts of reactants and the amounts of products in moles. 
D)  In aqueous reactions, quantities of reactants and products are generally expressed in terms of concentrations. 
E)  The actual yield is always equal to or less than the theoretical yield.

Question 19

Determine the theoretical yield of H2S (in moles) if 4.0 mol Al2S3 and 4.0 mol H2O are reacted according to the following balanced reaction. A possibly useful molar mass is Al2S3 = 150.17 g mol-1. Al2S3(s) + 6H2O(l) → 2Al(OH)3(s) + 3H2S(g)

Accepted Answer

A)  12 mol H2S 
B)  4.0 mol H2S 
C)  18 mol H2S 
D)  6.0 mol H2S 
E)  2.0 mol H2S

Question 20

Which of the following statements is TRUE?

Accepted Answer

A)  Electrolytes conduct electricity. 
B)  Strong acids are weak electrolytes. 
C)  Weak acids completely ionize in water. 
D)  Sugar solution conducts electricity. 
E)  AgNO3 is insoluble in water.

Exam 4: Chemical Reactions and Stoichiometry

Which one of the following is the best electrolyte?

How many millilitres of 0.260 mol L^-1 Na₂S are needed to react with 40.00 mL of 0.315 mol L^-1 AgNO₃? Na₂S(aq) + 2AgNO₃(aq) → 2NaNO₃(aq) + Ag₂S(s)

Identify the location of oxidation in an electrochemical cell.

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of ClO₂and H₂O in the balanced reaction? H₂O₂(l) + ClO₂(aq) → ClO₂⁻(aq) + O₂(g)

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Br₂and OH⁻ in the balanced reaction? Br₂(l) → BrO₃⁻(aq) + Br⁻(aq)

A stock solution of HNO₃ is prepared and found to contain 13.7 mol L^-1 of . If 25.0 mL of the stock solution is diluted to a final volume of 0.500 L, what is the concentration of the diluted solution?

How many millilitres of 0.152 mol L^-1 solution are needed to neutralize 50.00 mL of 0.0793 mol L^-1 NaOH?

Calculate the number of grams of solute in 500.0 mL of 0.189 mol L^-1 KOH.

Determine the oxidation state of S in MgSO₄.

Match the following. -H₂SO₄(aq) + 2LiOH(aq) → 2H₂O(l) + Li₂SO4(aq)

Carbonic acid can form water and carbon dioxide upon heating. How much carbon dioxide is formed from 6.20 g of carbonic acid? H₂CO₃ → H₂O + CO₂

Calculate the concentration (molarity) of a solution prepared by dissolving 72.8 g C₂H₆O in 2.34 L of water.

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Cdand Ag⁺ in the balanced reaction? Cd(s) + Ag⁺(aq) → Ag(s) + Cd²⁺(aq)

Match the following. -2HCl(aq) + (NH₄) ₂S(aq) → H₂S(g) + 2NH₄Cl(aq)

How many molecules of H₂S are required to form 79.0 g of sulfur according to the following reaction? Assume excess SO₂. 2H₂S(g) + SO₂(g) → 3S(s) + 2H₂O(l)

How many moles of Co²⁺ are present in 0.150 L of a 0.200 mol L^-1 solution of CoI₂ ?

What volume of 0.305 mol L^-1 AgNO₃ is required to react exactly with 155.0 mL of 0.274 mol L^-1 Na₂SO₄ solution? Hint: You will want to write a balanced reaction.

Which of the following statements is FALSE?

Determine the theoretical yield of H₂S (in moles) if 4.0 mol Al₂S₃ and 4.0 mol H₂O are reacted according to the following balanced reaction. A possibly useful molar mass is Al₂S₃= 150.17 g mol^-1. Al₂S₃(s) + 6H₂O(l) → 2Al(OH) ₃(s) + 3H₂S(g)

Which of the following statements is TRUE?

Exam 4: Chemical Reactions and Stoichiometry

Which one of the following is the best electrolyte?

How many millilitres of 0.260 mol L-1 Na2S are needed to react with 40.00 mL of 0.315 mol L-1 AgNO3? Na2S(aq) + 2AgNO3(aq) → 2NaNO3(aq) + Ag2S(s)

Identify the location of oxidation in an electrochemical cell.

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of ClO2 and H2O in the balanced reaction? H2O2(l) + ClO2(aq) → ClO2⁻(aq) + O2(g)

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Br2 and OH⁻ in the balanced reaction? Br2(l) → BrO3⁻(aq) + Br⁻(aq)

A stock solution of HNO3 is prepared and found to contain 13.7 mol L-1 of . If 25.0 mL of the stock solution is diluted to a final volume of 0.500 L, what is the concentration of the diluted solution?

How many millilitres of 0.152 mol L-1 solution are needed to neutralize 50.00 mL of 0.0793 mol L-1 NaOH?

Calculate the number of grams of solute in 500.0 mL of 0.189 mol L-1 KOH.

Determine the oxidation state of S in MgSO4.

Match the following. -H2SO4(aq) + 2LiOH(aq) → 2H2O(l) + Li2SO4(aq)

Carbonic acid can form water and carbon dioxide upon heating. How much carbon dioxide is formed from 6.20 g of carbonic acid? H2CO3 → H2O + CO2

Calculate the concentration (molarity) of a solution prepared by dissolving 72.8 g C2H6O in 2.34 L of water.

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Cd and Ag+ in the balanced reaction? Cd(s) + Ag+(aq) → Ag(s) + Cd2+(aq)

Match the following. -2HCl(aq) + (NH4) 2S(aq) → H2S(g) + 2NH4Cl(aq)

How many molecules of H2S are required to form 79.0 g of sulfur according to the following reaction? Assume excess SO2. 2H2S(g) + SO2(g) → 3S(s) + 2H2O(l)

How many moles of Co2+ are present in 0.150 L of a 0.200 mol L-1 solution of CoI2 ?

What volume of 0.305 mol L-1 AgNO3 is required to react exactly with 155.0 mL of 0.274 mol L-1 Na2SO4 solution? Hint: You will want to write a balanced reaction.

Which of the following statements is FALSE?

Determine the theoretical yield of H2S (in moles) if 4.0 mol Al2S3 and 4.0 mol H2O are reacted according to the following balanced reaction. A possibly useful molar mass is Al2S3 = 150.17 g mol-1. Al2S3(s) + 6H2O(l) → 2Al(OH) 3(s) + 3H2S(g)

Which of the following statements is TRUE?

How many millilitres of 0.260 mol L^-1 Na₂S are needed to react with 40.00 mL of 0.315 mol L^-1 AgNO₃? Na₂S(aq) + 2AgNO₃(aq) → 2NaNO₃(aq) + Ag₂S(s)

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of ClO₂and H₂O in the balanced reaction? H₂O₂(l) + ClO₂(aq) → ClO₂⁻(aq) + O₂(g)

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Br₂and OH⁻ in the balanced reaction? Br₂(l) → BrO₃⁻(aq) + Br⁻(aq)

A stock solution of HNO₃ is prepared and found to contain 13.7 mol L^-1 of . If 25.0 mL of the stock solution is diluted to a final volume of 0.500 L, what is the concentration of the diluted solution?

How many millilitres of 0.152 mol L^-1 solution are needed to neutralize 50.00 mL of 0.0793 mol L^-1 NaOH?

Calculate the number of grams of solute in 500.0 mL of 0.189 mol L^-1 KOH.

Determine the oxidation state of S in MgSO₄.

Match the following. -H₂SO₄(aq) + 2LiOH(aq) → 2H₂O(l) + Li₂SO4(aq)

Carbonic acid can form water and carbon dioxide upon heating. How much carbon dioxide is formed from 6.20 g of carbonic acid? H₂CO₃ → H₂O + CO₂

Calculate the concentration (molarity) of a solution prepared by dissolving 72.8 g C₂H₆O in 2.34 L of water.

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Cdand Ag⁺ in the balanced reaction? Cd(s) + Ag⁺(aq) → Ag(s) + Cd²⁺(aq)

Match the following. -2HCl(aq) + (NH₄) ₂S(aq) → H₂S(g) + 2NH₄Cl(aq)

How many molecules of H₂S are required to form 79.0 g of sulfur according to the following reaction? Assume excess SO₂. 2H₂S(g) + SO₂(g) → 3S(s) + 2H₂O(l)

How many moles of Co²⁺ are present in 0.150 L of a 0.200 mol L^-1 solution of CoI₂ ?

What volume of 0.305 mol L^-1 AgNO₃ is required to react exactly with 155.0 mL of 0.274 mol L^-1 Na₂SO₄ solution? Hint: You will want to write a balanced reaction.

Determine the theoretical yield of H₂S (in moles) if 4.0 mol Al₂S₃ and 4.0 mol H₂O are reacted according to the following balanced reaction. A possibly useful molar mass is Al₂S₃= 150.17 g mol^-1. Al₂S₃(s) + 6H₂O(l) → 2Al(OH) ₃(s) + 3H₂S(g)