Chapter 1

1. Balance the following in acidic solution:

(a) H₂O₂ +Sn²⁺→ H₂O+Sn⁴⁺

(b) PbO₂+Hg→Hg₂²⁺+Pb²⁺

(c) Al+Cr₂O₇^2-→Al³⁺+Cr³⁺

2. Balance the following in basic solution:

(a)SO₃^2-(aq) + Cu(OH)₂(s) → SO₄^2- (aq) + Cu(OH)(s)

(b) O₂(g) + Mn(OH)₂(s) → MnO₂(s)

(c) NO₃^-(aq) + H₂(g) → NO(g)

(d) Al(s) + CrO₄^2-(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) SiO₃^2-(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) SiO₄^4-

(c) Si₂H₆

(d) Si(OH)₄

(e) SiF₆^2-

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) →