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Question: When ethyl acetate was was hydrolysedin presemce of 0.1 M HCl, the rate constant was found to be 5.4...

When ethyl acetate was was hydrolysedin presemce of 0.1 M HCl, the rate constant was found to be 5.4 × 10−5^{-5}s−1^{-1}. But in presence of 0.1 M H2_2SO4_4 the rate constant was found to be 6.25 × 10−5^{-5}s−1^{-1}. Thus it may be concluded that:

A

H2_2SO4_4 furnishes more H+^+ than HCl

B

H2_2SO4_4 furnishes less H+^+ than HCl

C

both have the same strength

D

will depend on concentration of ethyl acetate

Answer

H2_2SO4_4 furnishes more H+^+ than HCl

Explanation

Solution

The ester hydrolysis is a pseudo-first order reaction, so the rate constant (k_obs) is proportional to the effective concentration of H⁺. For a 0.1 M solution of HCl, which is a strong monoprotic acid, the [H⁺] is approximately 0.1 M. However, for a 0.1 M solution of H₂SO₄, although the first proton dissociates completely, the second proton also dissociates to some extent, leading to an effective [H⁺] that is slightly more than 0.1 M. Since the observed rate constant with H₂SO₄ (6.25×10⁻⁵ s⁻¹) is greater than that with HCl (5.4×10⁻⁵ s⁻¹), it indicates that H₂SO₄ furnishes more H⁺.