The half-life of a substance in a first-order reaction is 15 minutes. The rate constant is

Question

The half-life of a substance in a first-order reaction is 15 minutes. The rate constant is (A) 2.46 × 102 min -1 (B) 4.62 × 10-2 min -1 (C) 3 × 10-5 min -1 (D) 3 × 10-9 min -1

Tardigrade Admin · Accepted Answer

k =(0.693/ t 1 / 2)=(0.693/15) =4.62 × 10-2 min -1

Q. The half-life of a substance in a first-order reaction is $15$ minutes. The rate constant is

$2.46 \times 1 0^{2} min^{- 1}$

$4.62 \times 1 0^{- 2} min^{- 1}$

$3 \times 1 0^{- 5} min^{- 1}$

$3 \times 1 0^{- 9} min^{- 1}$

$k = \frac{0.693}{t _{1/2}} = \frac{0.693}{15}$
$= 4.62 \times 1 0^{- 2} min^{- 1}$

Q. The half-life of a substance in a first-order reaction is 15 minutes. The rate constant is

2.46×102min−1

4.62×10−2min−1

3×10−5min−1

3×10−9min−1