Formic acid, which is a component of insect venom, has a K_a = 1.8 × 10^-4. What is the [H₃O⁺] in a solution that is initially 0.10 M formic acid, HCOOH? A) 4.2 × 10^-3 M B) 8.4 × 10^-3 M C) 1.8 × 10^-4 M D) 1.8 × 10^-5 M E) 1.8 × 10^-6 M

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Quizplus · Accepted Answer

The concentration of H₃O⁺ can be calculated using the formula for weak acid dissociation: [H₃O⁺] = √(K_a × [HCOOH]). Substituting the given values, [H₃O⁺] = √(1.8 × 10^-4 × 0.10) = 4.2 × 10^-3 M.

Formic Acid, Which Is a Component of Insect Venom, Has