For a reaction in a voltaic cell both ΔH° and ΔS° are positive. Which of the following statements is true?

a. ε°cell will decrease with an increase in temperature.
b. ΔG° > 0 for all temperatures.
c. ε°cell will increase with an increase in temperature.
d. ε°cell will not change when the temperature increases.
e. None of these choices statements is true.

c. ε°cell will increase with an increase in temperature.

Explanation:

Gibbs free energy change: ΔG = ΔH - TΔS. If  If ΔG is positive, then the reaction isn't feasible - it can't happen. For a reaction to be feasible, ΔG has to be negative, as T, the temperature, increases ΔG decreases towards  towards more a negative value and ΔG = - nFE.

a. ε°cell will decrease with an increase in temperature. False

Based on the above explanation, we can see that ε°cell will increase with a a temperature increase.

b. ΔG° > 0 for all temperatures. False

For a reaction to be feasible, ΔG has to be negative.

c. ε°cell will increase with an increase in temperature. TRUE

Based on the above explanation, we can see that ε°cell will increase with a a temperature increase.

d. ε°cell will not change when the temperature increases. False

This is false as ε°cell will increase when the temperature increases

e. None of these choices statements is true. False

Choice statement c is true.