ALL WORK MUST BE SHOWN WHERE APPROPRIATE. Proper handling of significant digits is assumed in all mathematical problems. Suggested time limit = 1 hour
1. Some hydrochloric acid is spilled on the lab floor. Sodium hydrogen carbonate is sprinkled on the spill to neutralize the acid. The balanced equation for the reaction that takes place is
NaHCO3 + HCl ® NaCl + CO2 + H2O
If 100.0 ml of 3.00 M HCl was spilled, what is the minimum amount (in grams) of NaHCO3 that must be sprinkled to neutralize all the acid in the spill?
2. Decide whether a precipitate will form when silver nitrate and lithium carbonate solutions are mixed. If a precipitate forms, write a net ionic equation for the reaction.
3. If 3.50 gram of C12H22O11 is dissolved in enough water to give 650 mL of solution, what is the molarity of the solution?
4. Describe how you would prepare 300 mL of 0.100 M (NH4)2SO4 starting with a 2.50 M stock solution.
5. From the following heats of reaction:
N2(g)+2 O2(g)®2 NO2(g)DH = +67.6 kJ
2 NO(g)+ O2(g)®2 NO2(g)DH = -113.2 kJ
calculate the heat of the reaction
N2(g)+O2(g)®2
NO(g)
6. Using data found in the thermodynamic tables in the appendix of your text, calculate the standard enthalpy change for the reaction:
NH3(g)+HCl(g)®NH4Cl(s)
7. a. Write a total ionic equation for the following and identify the spectator ions:
HC2H3O2(aq)+KOH (aq) ®KC2H3O2(aq)+H2O(l)
b. Write a net ionic equation for the reaction in a. above.
8. (10 pts) Determine the oxidation number of the underlined atom in each of the following:
a. H2CrO4
b.PO3-3
c.ClO2-
9. (10 pts) Which of the two reactions below is oxidation/reduction?
3Ca(OH)2 + 2 H3PO4® Ca3(PO4)2 + 6 H2O
Cu + 4 HNO3® Cu(NO3)2 + 2NO + 2 H2O
For the redox reaction, indicate the species
oxidized, the species reduced, the reducing agent and the oxidizing agent.