Question

pH of water at ${25}^{\circ }C$ is 7. If water is heated to ${70}^{\circ }C$.

• A. pH will decrease and water becomes acidic
• B. pH will decrease and water becomes basic
• C. pH remains constant at 7
• D. pH will decrease and water remains neutral

Answer 1

The correct option is D

pH will decrease and water remains neutral

Dissociation of $H_{2}O$ into $H^{+}andO{H}^{-}$increases with increase in temperature. Since concentration of $H^{+}$ ion increases, pH will decrease.