The rate constant for a reaction at the initial concentration of 2 × 10-2 mol L-1 is 4 × 10-3 mol L-1 min-1 . The half-life period for this reaction in seconds is

Question

The rate constant for a reaction at the initial concentration of 2 × 10-2 mol L-1 is 4 × 10-3 mol L-1 min-1 . The half-life period for this reaction in seconds is (A)  300  (B)  150  (C)  180  (D)  240

Tardigrade Admin · Accepted Answer

From the unit of rate constant, order of reaction is zero Hence, t1/2=([A]0/2k) =(2× 10-2/2×4× 10-3) minutes =2.5 minutes =150 seconds

Q. The rate constant for a reaction at the initial concentration of $2 \times 1 0^{- 2} m o l L^{- 1}$ is $4 \times 1 0^{- 3} m o l L^{- 1} mi n^{- 1}$ . The half-life period for this reaction in seconds is

$300$

$150$

$180$

$240$

From the unit of rate constant, order of reaction is zero
Hence, $t_{1/2} = \frac{[ A ] _{0}}{2 k}$
$= \frac{2 \times 1 0 ^{- 2}}{2 \times 4 \times 1 0 ^{- 3}}$ minutes
$= 2.5$ minutes
$= 150$ seconds

Q. The rate constant for a reaction at the initial concentration of 2×10−2molL−1 is 4×10−3molL−1min−1 . The half-life period for this reaction in seconds is

300

150

180

240