Chapter 1
1. Balance the following in acidic solution:
(a) H2O2 +Sn2+→ H2O+Sn4+
(b) PbO2+Hg→Hg22++Pb2+
(c) Al+Cr2O72-→Al3++Cr3+
2. Balance the following in basic solution:
(a)SO32-(aq) + Cu(OH)2(s) → SO42- (aq) + Cu(OH)(s)
(b) O2(g) + Mn(OH)2(s) → MnO2(s)
(c) NO3-(aq) + H2(g) → NO(g)
(d) Al(s) + CrO42-(aq) → Al(OH)3(s) + Cr(OH)4- (aq)
3. Balance the following reactions and write the reactions using cell notation. Ignore any inert electrodes, as they are never part of the half-reactions.
(a) Al(s) + Zr4+(aq) → Al3+(aq) + Zr(s)
(b) Ag+(aq) + NO(g) → Ag(s) + NO3-(aq) (acidic solution)
(c) SiO32-(aq) + Mg(s) → Si(s) + Mg(OH)2(s) (basic solution)
(d) ClO3-(aq) + MnO2(s) → Cl-(aq) + MnO4-(aq) (basic solution)
4. Determine the overall reaction and its standard cell potential at 25 °C for the reaction involving the galvanic cell made from a half-cell consisting of a silver electrode in 1 M silver nitrate solution and a half-cell consisting of a zinc electrode in 1 M zinc nitrate. Is the reaction spontaneous at standard conditions?
5. Consider a battery made from one half-cell that consists of a copper electrode in 1 M CuSO4 solution and another half-cell that consists of a lead electrode in 1 M Pb(NO3)2 solution.
(a) What are the reactions at the anode, cathode, and the overall reaction?
(b) What is the standard cell potential for the battery?
(c) Most devices designed to use dry-cell batteries can operate between 1.0 and 1.5 V. Could this cell be used to make a battery that could replace a dry-cell battery? Why or why not.
(d) Suppose sulfuric acid is added to the half-cell with the lead electrode and some PbSO4(s) forms. Would the cell potential increase, decrease, or remain the same?
6. How long would it take to reduce 1 mole of each of the following ions using the current indicated? Assume the voltage is sufficient to perform the reduction.
(a) Al3+, 1.234 A
(b) Ca2+, 22.2 A
(c) Cr5+, 37.45 A
(d) Au3+, 3.57 A
Chapter 2
1. The reaction of quicklime, CaO, with water produces slaked lime, Ca(OH)2, which is widely used in the construction industry to make mortar and plaster. The reaction of quicklime and water is highly exothermic: CaO(s) + H2O(l) → Ca(OH)2(s) ΔH = -350 kJ mol-1
(a) What is the enthalpy of reaction per gram of quicklime that reacts?
(b) How much heat, in kilojoules, is associated with the production of 1 ton of slakedlime?
2. Why is it possible for an active metal like aluminum to be useful as a structural metal?
3. Write a Lewis structure for each of the following molecules and ions:
(a) (CH3)3SiH
(b) SiO44-
(c) Si2H6
(d) Si(OH)4
(e) SiF62-
4. The following reactions are all similar to those of the industrial chemicals. Complete and balance the equations for these reactions:
(a) reaction of a weak base and a strong acid
NH3 +HClO4→
(b) preparation of a soluble silver salt for silver plating
Ag2CO3+HNO3→
(c) preparation of strontium hydroxide by electrolysis of a solution of strontium chloride (electrolysis)
SrCl2 (aq) + H2O(l) →