Question

What is the pH value of pure water at room temperature?

• A. 5
• B. 7
• C. 9
• D. 14

Hint:

{pH 7 = Neutral}. Pure water at room temperature has a pH of {7}.

Answer 1

The Correct Option is B

Concept: The pH scale measures the acidity or basicity of a solution and ranges from 0 to 14.

• pH<7 → Acidic
• pH = 7 → Neutral
• pH>7 → Basic (alkaline)

Pure water at room temperature (\(\approx 25^\circ C\)) has equal concentrations of hydrogen ions (\(H^+\)) and hydroxide ions (\(OH^-\)), making it neutral.
Step 1: Understand neutrality of pure water.
In pure water: \[ [H^+] = [OH^-] \] This balance results in a neutral pH.
Step 2: Determine the neutral value on the pH scale.
The neutral point on the pH scale is 7. Therefore, pure water has a pH of 7.