Practice question

Given: The K_a of phenol is 1.0 × 10⁻¹⁰. What is the pH of a 0.01 M solution? These values define the system as per NCERT data. Formula: K_a = x²/0.01, 1.0 × 10⁻¹⁰= x²/0.01, x² = 1.0 × 10⁻¹². This is the standard NCERT relation for this phenomenon. Substitution & Calculation: x = sqrt1.0 × 10⁻¹²= 1.0 × 10⁻⁶, pH = -log(1.0 × 10⁻⁶) = 6.0 . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.