Question

Seema squeezed a lemon and collected the juice in a glass. She realised that its sourness reduced when she added some water to it. What is the effect of addition of water on the concentration of hydroxide ions?

• A. It remains constant
• B. It increases
• C. It reduces
• D. It first increases and then decreases

Answer 1

Answer:

B. It increases

• Lemon juice is acidic.

• Adding water dilutes the solution, thereby decreasing the concentration of H+ ions.

• Since the concentration of H+ ions and OH- ions are inversely proportional (according to the ionic product of water, Kw = [H+][OH-] at a constant temperature), if [H+] decreases, [OH-]must increase.