Question
Consider the reaction, 2A + B → Products. When the concentration of B alone was doubled, the half-life did not change. When the concentration of An alone was doubled, the rate increased by two times. The unit of rate constant for this reaction is –
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L mol–1 s–1
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no unit
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mol L–1s–1
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s-1
Solution
A.
L mol–1 s–1
2A + B → Products
When conc. of B is doubled, the half-life did not change, hence reaction is of first order w.r.t. B. When the concentration of A is doubled, the reaction rate is doubled, hence reaction is of first order w.r.t. A. Hence over all order of reaction is 1 + 1 = 2. So, unit of rate constant L mol–1 s–1
