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1. Complete and balance the following equations. Give the oxidation numbers for all of the atoms in both products and reactants except for hydrogen and oxygen. Predict the sign of So for each reaction.
a. H3PO3(aq) + CrO42–(aq) H3PO4(aq) + Cr3+(aq)
b. Mn(s) + MnO4(aq) MnO2(s) + Mn(OH)2(s)

2. Consider the reaction between solid barium chloride and aqueous carbonic acid.
a. Write the balanced reaction.
b. Find Ho for the reaction in units of kJ.
c. Find So for the reaction in units of J/K.
d. Find Go for the reaction at 25 oC in units of kJ.
e. Find Go for the reaction at 75 oC in units of kJ.

3. Estimate Ka1 for carbonic acid using thermochemical data.

4. Estimate the cell potential at standard condition and 25 oC for the cell
Pt(s)|H3AsO3(aq)|H2AsO4(aq)|H+(aq)||H3AsO4(aq)|H3AsO3(aq)|H+(aq)|Pt(s)

5. Consider the cell: Al(s)|Al3+(aq)||Zn2+(aq)|Zn(s)
a. What is the balanced oxidation half-reaction?
b. What is the balanced reduction half-reaction?
c. What is the balanced net reaction?
d. What is the standard potential for the cell?
e. Is the reaction spontaneous or nonspontaneous? Why?