Question

Which of the changes to a voltaic cell of the general form X + + Y ⟶ X + Y + X++Y⟶X+Y+ would result in an increase in the cell potential (i.e., more positive E cell Ecell )?

Answer 1

The given question is incomplete. The complete question is as follows.

Which of the following changes to a voltaic cell of the general form  

X+ + Y ->X + Y+  would cause an increase in potential? (more positive Ecell)  

a. An increase in active ion concentration at the cathode.

b. An increase in active ion concentration at the anode.

c. An increase in temperature where K/Q > 1

d. An increase in temperature where K/Q < 1

Explanation:

In an electrochemical cell, the potential difference present within the two half cells is known as cell potential.

Formula for cell potential according to Nernst equation is as follows.

      $E^{o}_{cell} = E^{o} - \frac{2.303RT}{nF} log (\frac{\text{Anodic ion conc.}}{\text{Cathodic ion conc.}})$

So, more is the ion concentration at the cathode smaller will be the value deducted from $E^{o}$. Hence, more positive the value of $E^{o}_{cell}$ comes out.

Potential of a cell will increase under following conditions:

Whenever at the cathode there will occur an increase in concentration of active ion then there will also occur an increase in cell potential.

When the ratio of K is to Q (that is, \frac{K}{Q}) is greater than 1 then there will occur an increase in the cell potential.

Thus, we can conclude that following changes will lead to an increase in cell potential:

• An increase in temperature where K/Q > 1

• An increase in active ion concentration at the cathode.