Lesson eLearning

A 0.02 M solution of hydrochloric acid is prepared. What is its pH?

easy 1 mark Class 7 · Science · Acids, Bases and Salts
Answer
1.70

The correct answer is 1.70 — pH = -log₁₀(0.02) = -(-1.69897) = 1.69897 ≈ 1.70.

Step-by-step solution

  1. The concentration of H⁺ ions in a strong acid solution equals the molarity of the acid.
  2. Compute the pH using the formula pH = -log₁₀[H⁺].
  3. pH = -log₁₀(0.02) = -(-1.69897) = 1.69897 ≈ 1.70.
Common mistake: confusing pH calculation with negative sign

Concept tested: pH of strong acid

Published · How this solution was prepared and checked

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