For nitrous acid,HNO₂,K_a = 4.0 $\times$10^-⁴.Calculate the pH of 0.27 M HNO₂. A)1.98 B)0.57 C)3.97 D)12.02 E)none of these

Name: For nitrous acid,HNO 2 ,K a = 4.0 $\times$10 - 4 .Calculate the pH of 0.27 M HNO 2 . A)1.98 B)0.57 C)3.97 D)12.02 E)none of these
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Quizplus · Accepted Answer

To find the pH, use the formula for weak acid dissociation: Ka = [H+][NO2-]/[HNO2]. Assume [H+] = x, then Ka = x^2/(0.27-x) ≈ x^2/0.27. Solving x^2 = 4.0 × 10^-4 × 0.27 gives x ≈ 0.0107. Thus, pH = -log(0.0107) ≈ 1.98.

For Nitrous Acid,HNO2,Ka = 4 ×\times× 10-4

For Nitrous Acid,HNO₂,K_a = 4 $\times$ 10^-⁴