Question
The ${\left( {{{\partial E} \over {\partial T}}} \right)_P}$ of different types of half cells are as follows:
| A | B | C | D |
|---|---|---|---|
| $1 \times {10^{ - 4}}$ | $2 \times {10^{ - 4}}$ | $0.1 \times {10^{ - 4}}$ | $0.2 \times {10^{ - 4}}$ |
(Where E is the electromotive force)
Which of the above half cells would be preferred to be used as reference electrode?