Question

pH of water is 7 at 25°C. If water is heated to 80°C, its pH will:

• A. Decrease
• B. Remain the same
• C. \( \text{H}^+ \) concentration increases, \( \text{OH}^- \) concentration decreases
• D. Increase

Hint:

As temperature increases, the ionization of water increases, which leads to a decrease in pH.

Answer 1

The Correct Option is A

The pH of pure water depends on the ionization of water, which increases with temperature. At higher temperatures, the ionization of water increases, leading to a higher concentration of \( \text{H}^+ \) and \( \text{OH}^- \) ions, but since both increase equally, the pH will decrease. Thus, the correct answer is (1) Decrease.