The K_a of hydrazoic acid (HN₃)is 1.9 × 10^-5 at 25.0°C. What is the pH of a 0.40 M aqueous solution of HN₃?

Question

Quizplus · Accepted Answer

To find the pH, we first need to calculate the concentration of H⁺ ions using the formula for weak acids: Kₐ = [H⁺][N₃⁻]/[HN₃]. Assuming x is the concentration of H⁺ ions, we have Kₐ = x²/(0.40 - x). Solving for x gives approximately 2.75 × 10⁻³. The pH is then -log(2.75 × 10⁻³) ≈ 2.56.

The Ka of Hydrazoic Acid (HN3)is 1

The K_a of Hydrazoic Acid (HN₃)is 1