Question 1

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) +  O(l) →  (s)
In a particular experiment, 5.00 g sample of CaO is reacted with excess water and 6.11 g of  is recovered. What is the percent yield in this experiment?

Accepted Answer

A)  81.8 
B)  1.22 
C)  108 
D)  122 
E)  92.5

Question 2

What element is being reduced in the following (unbalanced) redox reaction? MnO4⁻ (aq) + H2C2O4(aq) → Mn2+(aq) + CO2(g)

Accepted Answer

A)  C 
B)  O 
C)  Mn 
D)  H

Question 3

A student prepared a stock solution by dissolving 10.0 g of KOH in enough water to make 150. mL of solution. She then took 15.0 mL of the stock solution and diluted it with enough water to make 65.0 mL of a final solution. What is the concentration of KOH for the final solution?

Accepted Answer

A)  0. 274 mol L-1 
B)  0. 356 mol L-1 
C)  2.81 mol L-1 
D)  3.65 mol L-1

Question 4

Based on the balanced chemical equation shown below, determine the molarity of a solution containing Fe2+(aq) if 40.00 mL of the Fe2+(aq) solution is required to completely react with 30.00 mL of a 0. 250 mol L-1 potassium bromate, KBrO3(aq), solution. The chemical equation for the reaction is: 
6Fe2+(aq) + BrO3-(aq) + 6H+(aq) → 6Fe3+(aq) + Br-(aq) + 3H2O(l)

Accepted Answer

A)  0. 0312 mol L-1 
B)  0. 188 mol L-1 
C)  1.12 mol L-1 
D)  2.00 mol L-1

Question 5

Identify the balanced equation to show the reaction of aqueous aluminum acetate with aqueous ammonium phosphate to form solid aluminum phosphate and aqueous ammonium acetate.

Accepted Answer

A)  Al(C2H3O2)2(aq) + (NH4)2PO4(aq) → AlPO4(s) + 2NH4C2H3O2(aq) 
B)  Al(C2H3O2)2(aq) + (NH3)2PO4(aq) → AlPO4(s) + 2NH3C2H3O2(aq) 
C)  Al(CO3)2(aq) + (NH3)2PO4(aq) → AlPO4(s) + 2NH3CO3(aq) 
D)  Al(C2H3O2)3(aq) + (NH4)3PO4(aq) → AlPO4(s) + 3NH4C2H3O2(aq) 
E)  Al(CO2)3(aq) + (NH4)3PO3(aq) → AlPO3(s) + 3NH4CO2(aq)

Question 6

Lead ions can be precipitated from aqueous solutions by the addition of aqueous iodide:  (aq) +  (aq) →  (s) Lead iodide is virtually insoluble in water so that the reaction appears to go to completion. How many millilitres of 3.550 mol L-1 HI(aq) must be added to a solution containing 0.700 mol of  to completely precipitate the lead?

Accepted Answer

A)  197 mL 
B)  0.197 mL 
C)  394 mL 
D)  0.394 mL 
E)  2.54 × 10-3 mL

Question 7

How many moles of LiI are contained in 258.6 mL of a 0.0296 mol L-1 LiI solution?

Accepted Answer

A)  1.31 × 10-3 mol 
B)  8.74 × 10-3 mol 
C)  1.14 × 10-3 mol 
D)  3.67 × 10-3 mol 
E)  7.65 × 10-3 mol

Question 8

A solution is prepared by mixing 70.0 mL of 0.100 mol L-1 HCl and 30.0 mL of 0.200 mol L-1 NaCl. What is the molarity of chloride ion in this solution?

Accepted Answer

A)  0.186 mol L-1 
B)  7.69 mol L-1 
C)  6.50 mol L-1 
D)  0.0100 mol L-1 
E)  0.130 mol L-1

Question 9

Lithium and nitrogen react to produce lithium nitride: 6Li(s) +  (g) →  N(s)
How many moles of  are needed to react with 0.400 mol of lithium?

Accepted Answer

A)  2.40 
B)  0.400 
C)  0.133 
D)  1.2 
E)  0.0667

Question 10

Which of the following pairs of aqueous solutions will form a precipitate when mixed?

Accepted Answer

A)  K2CO3 + NaCl 
B)  Na2SO4 + KOH 
C)  CaS + Na2SO4 
D)  None of these solution pairs will produce a precipitate. 
E)  All of these solution pairs will produce a precipitate.

Question 11

How many litres of a 0.0550 mol L-1 KCl solution contain 0.163 moles of KCl?

Accepted Answer

A)  3.37 L 
B)  1.48 L 
C)  8.97 L 
D)  2.96 L 
E)  1.12 L

Question 12

How many grams of NaCl are required to make 250.0 mL of a 3.000 mol L-1 solution?

Accepted Answer

A)  58.40 g 
B)  175.3 g 
C)  14.60 g 
D)  43.83 g

Question 13

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements:  (s) → 2Na(s) +  (g) How many moles of  are produced by the decomposition of 2.54 mol of sodium azide?

Accepted Answer

A)  1.69 
B)  7.62 
C)  3.81 
D)  0.847 
E)  1.27

Question 14

What are the required coefficients to properly balance the following chemical reaction? 
SO2(g) + O2(g) + H2O(l) → H2SO4(aq)

Accepted Answer

A)  1, 1, 1, 1 
B)  1, 2, 1, 2 
C)  1, 2, 2, 1 
D)  2, 1, 2, 2 
E)  2, 1, 1, 2

Question 15

Lithium and nitrogen react to produce lithium nitride: 6Li(s) +  (g) →  N(s)
How many moles of lithium nitride are produced when 0.450 mol of lithium react in this fashion?

Accepted Answer

A)  0.150 
B)  0.900 
C)  0.0750 
D)  1.35 
E)  0.225

Question 16

Identify the balanced equation to show the reaction of sulfurous acid with lithium hydroxide to form water and lithium sulfite.

Accepted Answer

A)  H2SO4(aq) + LiOH(aq) → H2O(l) + Li2SO4(aq) 
B)  H2SO3(aq) + 2LiOH(aq) → 2H2O(l) + Li2SO3(aq) 
C)  HSO3(aq) + LiOH(aq) → H2O(l) + LiSO3(aq) 
D)  HSO4(aq) + LiOH(aq) → H2O(l) + LiSO4(aq) 
E)  H2S(aq) + 2LiOH(aq) → 2H2O(l) + Li2S(aq)

Question 17

What are the required coefficients to properly balance the following chemical reaction? 
N2H4(l) → NH3(g) + N2(g)

Accepted Answer

A)  3, 4, 1 
B)  2, 3, 2 
C)  3, 4, 4 
D)  1, 4, 3 
E)  2, 2, 1

Question 18

How many moles of NaCl are required to make 250 mL of a 3.00 mol L-1 solution?

Accepted Answer

A)  750 moles 
B)  0.750 moles 
C)  3 moles 
D)  0.250 moles

Question 19

In an acid-base neutralization reaction, 38.74 mL of 0.500 mol L-1 potassium hydroxide reacts with 50.00 mL of sulfuric acid solution. What is the concentration of the H2SO4 solution?

Accepted Answer

A)  0. 194 mol L-1 
B)  0. 387 mol L-1 
C)  0. 775 mol L-1 
D)  1.29 mol L-1

Question 20

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of H⁺ and Fe3+ in the balanced reaction? Fe2+(aq) + MnO4⁻(aq) → Fe3+(aq) + Mn2+(aq)

Accepted Answer

A)  H⁺ = 2, Fe3+ = 3 
B)  H⁺ = 8, Fe3+ = 5 
C)  H⁺ = 3, Fe3+ = 2 
D)  H⁺ = 5, Fe3+ = 1 
E)  H⁺ = 8, Fe3+ = 1

Exam 4: Chemical Reactions and Stoichiometry

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) + O(l) → (s) In a particular experiment, 5.00 g sample of CaO is reacted with excess water and 6.11 g of is recovered. What is the percent yield in this experiment?

What element is being reduced in the following (unbalanced) redox reaction? MnO₄⁻ (aq) + H₂C₂O₄(aq) → Mn²⁺(aq) + CO₂(g)

A student prepared a stock solution by dissolving 10.0 g of KOH in enough water to make 150. mL of solution. She then took 15.0 mL of the stock solution and diluted it with enough water to make 65.0 mL of a final solution. What is the concentration of KOH for the final solution?

Identify the balanced equation to show the reaction of aqueous aluminum acetate with aqueous ammonium phosphate to form solid aluminum phosphate and aqueous ammonium acetate.

How many moles of LiI are contained in 258.6 mL of a 0.0296 mol L^-1 LiI solution?

A solution is prepared by mixing 70.0 mL of 0.100 mol L^-1 HCl and 30.0 mL of 0.200 mol L^-1 NaCl. What is the molarity of chloride ion in this solution?

Lithium and nitrogen react to produce lithium nitride: 6Li(s) + (g) → N(s) How many moles of are needed to react with 0.400 mol of lithium?

Which of the following pairs of aqueous solutions will form a precipitate when mixed?

How many litres of a 0.0550 mol L^-1 KCl solution contain 0.163 moles of KCl?

How many grams of NaCl are required to make 250.0 mL of a 3.000 mol L^-1 solution?

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: (s) → 2Na(s) + (g) How many moles of are produced by the decomposition of 2.54 mol of sodium azide?

What are the required coefficients to properly balance the following chemical reaction? SO₂(g) + O₂(g) + H₂O(l) → H₂SO₄(aq)

Lithium and nitrogen react to produce lithium nitride: 6Li(s) + (g) → N(s) How many moles of lithium nitride are produced when 0.450 mol of lithium react in this fashion?

Identify the balanced equation to show the reaction of sulfurous acid with lithium hydroxide to form water and lithium sulfite.

What are the required coefficients to properly balance the following chemical reaction? N₂H₄(l) → NH₃(g) + N₂(g)

How many moles of NaCl are required to make 250 mL of a 3.00 mol L^-1 solution?

In an acid-base neutralization reaction, 38.74 mL of 0.500 mol L^-1 potassium hydroxide reacts with 50.00 mL of sulfuric acid solution. What is the concentration of the H₂SO₄ solution?

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of H⁺and Fe³⁺ in the balanced reaction? Fe²⁺(aq) + MnO₄⁻(aq) → Fe³⁺(aq) + Mn²⁺(aq)

Exam 4: Chemical Reactions and Stoichiometry

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) + O(l) → (s) In a particular experiment, 5.00 g sample of CaO is reacted with excess water and 6.11 g of is recovered. What is the percent yield in this experiment?

What element is being reduced in the following (unbalanced) redox reaction? MnO4⁻ (aq) + H2C2O4(aq) → Mn2+(aq) + CO2(g)

A student prepared a stock solution by dissolving 10.0 g of KOH in enough water to make 150. mL of solution. She then took 15.0 mL of the stock solution and diluted it with enough water to make 65.0 mL of a final solution. What is the concentration of KOH for the final solution?

Identify the balanced equation to show the reaction of aqueous aluminum acetate with aqueous ammonium phosphate to form solid aluminum phosphate and aqueous ammonium acetate.

How many moles of LiI are contained in 258.6 mL of a 0.0296 mol L-1 LiI solution?

A solution is prepared by mixing 70.0 mL of 0.100 mol L-1 HCl and 30.0 mL of 0.200 mol L-1 NaCl. What is the molarity of chloride ion in this solution?

Lithium and nitrogen react to produce lithium nitride: 6Li(s) + (g) → N(s) How many moles of are needed to react with 0.400 mol of lithium?

Which of the following pairs of aqueous solutions will form a precipitate when mixed?

How many litres of a 0.0550 mol L-1 KCl solution contain 0.163 moles of KCl?

How many grams of NaCl are required to make 250.0 mL of a 3.000 mol L-1 solution?

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: (s) → 2Na(s) + (g) How many moles of are produced by the decomposition of 2.54 mol of sodium azide?

What are the required coefficients to properly balance the following chemical reaction? SO2(g) + O2(g) + H2O(l) → H2SO4(aq)

Lithium and nitrogen react to produce lithium nitride: 6Li(s) + (g) → N(s) How many moles of lithium nitride are produced when 0.450 mol of lithium react in this fashion?

Identify the balanced equation to show the reaction of sulfurous acid with lithium hydroxide to form water and lithium sulfite.

What are the required coefficients to properly balance the following chemical reaction? N2H4(l) → NH3(g) + N2(g)

How many moles of NaCl are required to make 250 mL of a 3.00 mol L-1 solution?

In an acid-base neutralization reaction, 38.74 mL of 0.500 mol L-1 potassium hydroxide reacts with 50.00 mL of sulfuric acid solution. What is the concentration of the H2SO4 solution?

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of H⁺ and Fe3+ in the balanced reaction? Fe2+(aq) + MnO4⁻(aq) → Fe3+(aq) + Mn2+(aq)

What element is being reduced in the following (unbalanced) redox reaction? MnO₄⁻ (aq) + H₂C₂O₄(aq) → Mn²⁺(aq) + CO₂(g)

How many moles of LiI are contained in 258.6 mL of a 0.0296 mol L^-1 LiI solution?

A solution is prepared by mixing 70.0 mL of 0.100 mol L^-1 HCl and 30.0 mL of 0.200 mol L^-1 NaCl. What is the molarity of chloride ion in this solution?

How many litres of a 0.0550 mol L^-1 KCl solution contain 0.163 moles of KCl?

How many grams of NaCl are required to make 250.0 mL of a 3.000 mol L^-1 solution?

What are the required coefficients to properly balance the following chemical reaction? SO₂(g) + O₂(g) + H₂O(l) → H₂SO₄(aq)

What are the required coefficients to properly balance the following chemical reaction? N₂H₄(l) → NH₃(g) + N₂(g)

How many moles of NaCl are required to make 250 mL of a 3.00 mol L^-1 solution?

In an acid-base neutralization reaction, 38.74 mL of 0.500 mol L^-1 potassium hydroxide reacts with 50.00 mL of sulfuric acid solution. What is the concentration of the H₂SO₄ solution?

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of H⁺and Fe³⁺ in the balanced reaction? Fe²⁺(aq) + MnO₄⁻(aq) → Fe³⁺(aq) + Mn²⁺(aq)