1 What is the oxidation number of the following:

a) P in H₃PO₃

b) O in K₂CrO₄

c) Cl in ClO₃^-

d) H in NaH

e) N in N₂O

2. Balance the following 1/2 cell reactions in acid solutions:

a) Cr₂O₇-2 = Cr+3

b) V⁺² = VO2⁺

c) C₂O₄-2 = CO₂

d) Z⁺ = ZO₂H^-

3. Balance the following equations:

a) Sn⁺² + Fe⁺³ = Sn⁺⁴ + Fe⁺²

b) MnO₄ - + C₂O₄ ^-2+ H + = CO₂ + H₂O + Mn⁺²

c) C₃H₈ + O₂ = CO₂ + H₂O

 d) Cr₂O₇ ^-2+ Fe ⁺²+ H ⁺=> Cr ⁺³+ Fe⁺³ + H₂O

4. a) In 3 a above, what is being oxidized? b) What is the reducing agent? c) In the balanced equation, how many electrons are transferred.

5. In what way are the burning of coal, the metabolism of food, and the rusting of a metal like iron all related to one another?

6. Iron ore, Fe₃O₄, is used to produce iron by reaction with coke. Assuming coke is predominately C(g) write the balance chemical reaction equation for the process and indicate what is being reduced and what is the reducing agent.

7. Write a balanced reaction equation for each of the following:

a) sugar is oxidized with oxygen to CO₂ and water.

b) VO₂⁺ can be reduced to VO⁺² using Zn as a reducing agent.