The rate of first order reaction, $A \to \;products$, is $7.5 \times {10^{ - 4}}\;{\rm{mol}}\;{\rm{litr}}{{\rm{e}}^{ - 1}}\;{\sec ^{ - 1}}.$ If the concentration of $A\;is\;0.5\;{\rm{mol}}\;{\rm{litr}}{{\rm{e}}^{ - 1}}$ the rate constant is:

$3.75 \times {10^{ - 4}}\;{\sec ^{ - 1}}$

$2.5 \times {10^{ - 5}}\;{\sec ^{ - 1}}$

$8.0 \times {10^{ - 4}}\;{\sec ^{ - 1}}$

NEET UG CHEMISTRY MCQ: CHEMICAL KINETICS

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Application +4 | -1

The rate of first order reaction,

A \to \;products

, is

7.5 \times {10^{ - 4}}\;\mathrm{mol}\;\mathrm{litr}{\mathrm{e}^{ - 1}}\;{\sec ^{ - 1}}.

If the concentration of

A\;is\;0.5\;\mathrm{mol}\;\mathrm{litr}{\mathrm{e}^{ - 1}}

the rate constant is:

View answer and explanation

Correct option: C

1.5 \times {10^{ - 3}}\;{\sec ^{ - 1}}

Option C (

1.5 \times {10^{ - 3}}\;{\sec ^{ - 1}}

) is correct because for a first-order reaction, k = rate/[A].