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प्रश्न
Answer the following in brief.
Give one example and explain why it is pseudo-first-order.
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उत्तर
Example: Consider the hydrolysis of methyl acetate.
\[\ce{CH3COOCH3_{(aq)} + H2O_{(l)} -> CH3COOH_{(aq)} + CH3OH_{(aq)}}\]
The rate law is rate = k' [CH3COOCH3][H2O]
Explanation: The reaction was expected to follow the second-order kinetics, however, obeys the first order. The reason is that solvent water is present in such large excess that the change in its concentration is negligible compared to the initial one or its concentration remains constant. Thus [H2O] = constant = k''. The rate law becomes rate = k' [CH3COOCH3]k'' = k [CH3COOCH3]
where, k = k'k''
The reaction is thus of first order.
संबंधित प्रश्न
Answer the following in brief.
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\[\ce{2NH_{3(g)} -> N_{2(g)} + 3H_{2(g)}}\]
Write a mathematical expression for integrated rate law for zero-order reaction.
For a first-order reaction \[\ce{A -> B}\] the rate constant is x min−1. If the initial concentration of A is 0.01 M, the concentration of A after one hour is given by the expression.
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The order of the reaction for which the unit of rate constant is s−1 is ____________.
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What is the unit of rate constant for the zero order reaction?
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Calculate half life of reaction if rate constant of first order reaction is 0.0178 minute−1.
