Cell EMF under Nonstandard Conditions (Section)What is the effect on the emf of the cell s...

Cell EMF under Nonstandard Conditions (Section)

What is the effect on the emf of the cell shown in Figure, which has the overall reaction Zn(s) + 2 H+(aq)→ Zn2+(aq) + H2(g), for each of the following changes?

Figure A voltaic cell using a standard hydrogen electrode (SHE). The anode half-cell is Zn metal in a Zn(NO3)2(aq) solution, and the cathode half-cell is the SHE in a HNO3(aq) solution.

Why do Na+ ions migrate into the cathode half-cell as the cell reaction proceeds?

(a) The pressure of the H2 gas is increased in the cathode halfcell. (b) Zinc nitrate is added to the anode half-cell. (c) Sodium hydroxide is added to the cathode half-cell, decreasing [H+]. (d) The surface area of the anode is doubled.