JEE Main · 2024 · 08 Apr 2024 · Shift 1 · Chemical Kinetics

Consider the following reaction

A + B \to C

The time taken for A to become

1/ 4^{th}

of its initial concentration is twice the time taken to become 1/2 of the same. Also, when the change of concentration of B is plotted against time, the resulting graph gives a straight line with a negative slope and a positive intercept on the concentration axis.

The overall order of the reaction is ______.

Answer: 1

Solution

t_{1/4} = 2 t_{1/2}

(time to fall to

\frac{1}{4}

is twice the time to fall to

\frac{1}{2}

) is the signature of a first-order dependence on A. A straight-line

[B]

-vs-time plot means B decays at constant rate — zero order in B. Overall order

= 1 + 0 = 1

JEE Main · 2024 · 08 Apr 2024 · Shift 1 · Integer answer

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