General Chemistry I - Exam 2: Pitt
FROM SAMPLE TEST:
1. A 125 mL sample of orange juice was titrated using a redox reaction to the
equivalence point with the addition of 7.6 mL of a 0.025 M iodine (I₂)
solution. What is the concentration of vitamin C (C₆H₈O₆) in this sample?
Reaction:
C₆H₈O₆ (aq) + I₂ (aq) → C₆H₆O₆ (aq) + 2I⁻ (aq) + 2H⁺ (aq)
Options:
A. 30 mM
B. 15 mM
C. 19 mM
D. 0.30 mM
E. 0.15 mM
Correct Answer: E
2. How many moles are there in 1.50 grams of ethanol (C₂H₅OH)?
Options:
A. 0.0145 mol
B. 0.0326 mol
C. 30.7 mol
D. 69.0 mol
Correct Answer: B
3. Given the reaction:
Cu + 2 AgNO₃ → 2 Ag + Cu(NO₃)₂
How many moles of Ag will be produced from 46.0 grams of Cu?
Correct Answer: 1.45 moles
4. Given the reaction:
4 Fe + 3 O₂ → 2 Fe₂O₃
, How many moles of Fe₂O₃ will be produced from 27 grams of Fe?
Correct Answer: 0.242 moles
5. Given the reaction:
Zn + 2 HCl → ZnCl₂ + H₂
How many moles of ZnCl₂ will be produced from 55.0 grams of Zn?
Correct Answer: 0.841 moles
6. What is a limiting reactant?
Correct Answer: The reactant that has the smallest stoichiometric amount in a
reactant mixture and consequently limits the amount of product in a chemical
reaction.
7. Given the reaction:
NaCl + AgNO₃ → AgCl + NaNO₃
If 5.00 grams of NaCl and 103 grams of AgNO₃ are used, which compound is
the limiting reactant?
Correct Answer: NaCl
8. Given the reaction:
Cu + 2 AgNO₃ → 2 Ag + Cu(NO₃)₂
How many grams of Ag will be produced from 5.00 grams of Cu and 1.00
gram of AgNO₃?
Correct Answer: 0.640 grams
9. Given the reaction:
CH₄ + 2 O₂ → CO₂ + 2 H₂O
How many grams of CO₂ will be produced from 15.0 grams of CH₄ and 114
grams of O₂?
Correct Answer: 41.2 grams
10. Given the reaction:
N₂ + 3 H₂ → 2 NH₃
This reaction gave an actual yield of 98.67 grams of NH₃, from 85.90 grams
of N₂ and 21.66 grams of H₂. What is the percent yield of NH₃?
Correct Answer: 94.49%
, 11. What is molarity (M)?
Correct Answer: Amount of Solute (in mols) / Volume of Solution (in Liters)
12. A 0.200 L cup of tea contains 3.765 grams of sucrose (molar mass = 342.3
g/mol). What is the molarity of sucrose in the tea?
Correct Answer: 0.0550 M
13. A 0.250 L sample of seawater contains 77.4 grams of NaCl (molar mass =
58.44 g/mol). What is the molarity of NaCl in the seawater?
Correct Answer: 5.30 M
14. A 2.00 M hydrochloric acid solution is prepared with a total volume of 0.350
L (molar mass HCl = 36.46 g/mol). What mass of HCl is needed?
Correct Answer: 25.5 grams
15. A 0.839 M acetic acid solution is prepared with a total volume of 500 mL
(molar mass = 60.05 g/mol). What mass of acetic acid is needed?
Correct Answer: 25.2 grams
16. A 0.385 M MnSO₄ solution is prepared using 57.0 grams of MnSO₄ (molar
mass = 151.0 g/mol). What is the volume of the solution?
Correct Answer: 0.980 L
17. Suppose a laboratory procedure calls for 3.00 L of 0.500 M CaCl₂ solution,
but only a 10 M CaCl₂ solution is available. What volume of the 10 M
solution must be diluted?
Correct Answer: 0.15 L
18. What's the formula for dilution?
Correct Answer: M₁ × V₁ = M₂ × V₂
19. If you have 0.200 L of a 15 M NaOH solution but need a 3 M NaOH solution,
to what volume should you dilute it?
Correct Answer: 1 L
20. A procedure calls for 500 mL of 0.450 M NaCl, but only a 5 M NaCl solution
is available. What volume of the 5 M solution must be diluted?
Correct Answer: 45 mL
FROM SAMPLE TEST:
1. A 125 mL sample of orange juice was titrated using a redox reaction to the
equivalence point with the addition of 7.6 mL of a 0.025 M iodine (I₂)
solution. What is the concentration of vitamin C (C₆H₈O₆) in this sample?
Reaction:
C₆H₈O₆ (aq) + I₂ (aq) → C₆H₆O₆ (aq) + 2I⁻ (aq) + 2H⁺ (aq)
Options:
A. 30 mM
B. 15 mM
C. 19 mM
D. 0.30 mM
E. 0.15 mM
Correct Answer: E
2. How many moles are there in 1.50 grams of ethanol (C₂H₅OH)?
Options:
A. 0.0145 mol
B. 0.0326 mol
C. 30.7 mol
D. 69.0 mol
Correct Answer: B
3. Given the reaction:
Cu + 2 AgNO₃ → 2 Ag + Cu(NO₃)₂
How many moles of Ag will be produced from 46.0 grams of Cu?
Correct Answer: 1.45 moles
4. Given the reaction:
4 Fe + 3 O₂ → 2 Fe₂O₃
, How many moles of Fe₂O₃ will be produced from 27 grams of Fe?
Correct Answer: 0.242 moles
5. Given the reaction:
Zn + 2 HCl → ZnCl₂ + H₂
How many moles of ZnCl₂ will be produced from 55.0 grams of Zn?
Correct Answer: 0.841 moles
6. What is a limiting reactant?
Correct Answer: The reactant that has the smallest stoichiometric amount in a
reactant mixture and consequently limits the amount of product in a chemical
reaction.
7. Given the reaction:
NaCl + AgNO₃ → AgCl + NaNO₃
If 5.00 grams of NaCl and 103 grams of AgNO₃ are used, which compound is
the limiting reactant?
Correct Answer: NaCl
8. Given the reaction:
Cu + 2 AgNO₃ → 2 Ag + Cu(NO₃)₂
How many grams of Ag will be produced from 5.00 grams of Cu and 1.00
gram of AgNO₃?
Correct Answer: 0.640 grams
9. Given the reaction:
CH₄ + 2 O₂ → CO₂ + 2 H₂O
How many grams of CO₂ will be produced from 15.0 grams of CH₄ and 114
grams of O₂?
Correct Answer: 41.2 grams
10. Given the reaction:
N₂ + 3 H₂ → 2 NH₃
This reaction gave an actual yield of 98.67 grams of NH₃, from 85.90 grams
of N₂ and 21.66 grams of H₂. What is the percent yield of NH₃?
Correct Answer: 94.49%
, 11. What is molarity (M)?
Correct Answer: Amount of Solute (in mols) / Volume of Solution (in Liters)
12. A 0.200 L cup of tea contains 3.765 grams of sucrose (molar mass = 342.3
g/mol). What is the molarity of sucrose in the tea?
Correct Answer: 0.0550 M
13. A 0.250 L sample of seawater contains 77.4 grams of NaCl (molar mass =
58.44 g/mol). What is the molarity of NaCl in the seawater?
Correct Answer: 5.30 M
14. A 2.00 M hydrochloric acid solution is prepared with a total volume of 0.350
L (molar mass HCl = 36.46 g/mol). What mass of HCl is needed?
Correct Answer: 25.5 grams
15. A 0.839 M acetic acid solution is prepared with a total volume of 500 mL
(molar mass = 60.05 g/mol). What mass of acetic acid is needed?
Correct Answer: 25.2 grams
16. A 0.385 M MnSO₄ solution is prepared using 57.0 grams of MnSO₄ (molar
mass = 151.0 g/mol). What is the volume of the solution?
Correct Answer: 0.980 L
17. Suppose a laboratory procedure calls for 3.00 L of 0.500 M CaCl₂ solution,
but only a 10 M CaCl₂ solution is available. What volume of the 10 M
solution must be diluted?
Correct Answer: 0.15 L
18. What's the formula for dilution?
Correct Answer: M₁ × V₁ = M₂ × V₂
19. If you have 0.200 L of a 15 M NaOH solution but need a 3 M NaOH solution,
to what volume should you dilute it?
Correct Answer: 1 L
20. A procedure calls for 500 mL of 0.450 M NaCl, but only a 5 M NaCl solution
is available. What volume of the 5 M solution must be diluted?
Correct Answer: 45 mL
