Question

A solution has $pH=7$ at room temperature. At ${100}^0$C, the same solution will be:

• A. Acidic
• B. Basic
• C. Neutral
• D. Can't determined

Answer 1

The correct option is B Basic

At room temperature (i.e. ${25}^{o}C$), at a pH of 7, water is neutral. Since the dissociation of water is an endothermic process, as the temperature increases, the concentration of $H^{+}$ ions and $O{H}^{-}$ increases and hence, the pH and pOH of water both decrease by the same amount. Since the concentrations of both the ions is still the same, the solution is still neutral. The only difference is that the value of pH at this higher temperature would be lower than 7 – which would be the same as the value of pOH.