Chemical Reactions in Solution

22 Oct Chemical Reactions in Solution

Written Assignment 5: Chemical Reactions in Solution

Answer all assigned questions and problems, and show all work.

1. Define electrolyte and nonelectrolyte and identify each of the following substances as a strong electrolyte, weak electrolyte, or nonelectrolyte: (5 points)

(Reference: Chang 4.9)

2. Write ionic and net ionic equations for the following reactions: (8 points)

a. AgNO3 + Na2SO4 →

b. BaCl2 + ZnSO4 →

c. (NH4)2CO3 + CaCl2  →

d. NaNO3 + KCl  →

(Reference: Chang 4.21)

3. With reference to Table 4.2, suggest one method by which you might separate (a) K+ from Ag+, (b) Ba2+ from Pb2+, (c) NH4+ from Ca2+, and (d) Ba2+ from Cu2+. All cations are assumed to be in aqueous solution, and the common anion is the nitrate ion. (8 points)

(Reference: Chang 4.24)

4. Give the oxidation number of the underlined atoms in the following molecules and ions: (7 points)

1. ClF
2. IF7 –       
3. CH4 –       
4. C2H2-
5. C2H4-       
6. K2CrO4 –       
7. K2Cr2O7       – 
8. KMnO4 –       
9. NaHCO3 –       
10. O2 –       
11. NaIO3 –       
12. K2O –       
13. PF6 –       
14. AuCl4 –       

(Reference: Chang 4.47)

5. For the following reactions, identify the type (combination, combustion, decomposition, displacement, methathesis [double-displacement)] neutralization), balance the reaction, and for the redox reactions identify the oxidizing agent and reducing agent. (12 points)

(a) CH4 + O2 → CO2 + H2O

(b) HCl + NaOH → H2O + NaCl

(c) H2 + O2 → H2O

(d) CaCO3 + HCl → CaCl2 + CO2 + H2O

(e) Zn + HCl → ZnCl2 + H2

(f) NaCl → Na + Cl2

6. Calculate the molarity of each of the following solutions: (4 points)

a. 29.0 g of ethanol (C2H5OH) in 545 mL of solution

b. 9.00 g of sodium chloride (NaCl) in 86.4 mL of solution

(Reference: Chang 4.65)

7. Calculate the mass of KI in grams required to prepare 5.00 × 102 mL of a 2.80 M solution. (3 points)

(Reference: Chang 4.59)

8. How many grams of NaCl are required to precipitate most of the Ag+ ions from 2.50 × 102 mL of 0.0113 M AgNO3 solution? Write the net ionic equation for the reaction. (5 points)

(Reference: Chang 4.53)

9. What volume of 0.416M Mg(NO3)2 should be added to 255 mL of 0.102 M KNO3 to produce a solution with a concentration of 0.278 M NO3– ions? Assume volumes are additive. (4 points)

(Reference: Chang 4.69)

10. Describe how to prepare 1.00 L of 0.646 M HCl solution, starting with 2.00 M HCl solution. (4 points)

(Reference: Chang 4.73)

11. Calculate the volume in mL of a 1.420 M NaOH solution required to titrate the following solutions: (9 points)

a. 25.00 mL of a 2.430 M HCl solution

b. 25.00 mL of a 4.500 M H2SO4 solution

c. 25.00 mL of a 1.500 M H3PO4 solution

(Reference: Chang 4.91)

12. A 325 mL sample of solution contains 25.3 g of CaCl2. (4 points)

a. Calculate the molar concentration of Cl– in the solution.

b. How many grams of Cl– are in 0.100 L of this solution?

(Reference: Chang 4.148)

13. A student mixes 100.0 mL of 0.500 M AgNO3 with 100.0 mL of 0.500 M CaCl2. (8 points)

a. Write the balanced molecular equation for the reaction.

b. Write the net ionic equation for the reaction.

c. How many grams of precipitate will form?

d. What is the concentration of Ag+, NO3‒, Ca2+, and Cl‒ in the final solution (assume volumes are additive).

14. Based on oxidation number consideration, explain why carbon monoxide is flammable but carbon dioxide is not. (4 points)

(Reference: Chang 4.141)

15. The alcohol content in a 10.0 g sample of blood from a driver required 4.23 mL of 0.07654 M K2Cr2O7 for titration. If the current legal limit of blood alcohol content is 0.08 percent by mass, should the driver be prosecuted for drunken driving? What is the percent alcohol in the driver’s blood? (7 points)

(Reference: Chang 4.154)

16. Write balanced chemical equations for the following: (8 points)

a. A solution of sulfuric acid (battery acid) is neutralized with a solution of sodium hydroxide.

b. The combustion of iron metal produces iron(III) oxide (rust).

c. When sodium metal is dropped into water, it fizzes.

d. The science fair “volcano reaction” is produced by mixing sodium bicarbonate (baking soda) with vinegar (a solution of acetic acid HC2H3O2).