For a reaction with rate law rate = k[A]^2[B], the initial rate is 5.40x10^-4 M s^-1 when [A] = 0.30 M and [B] = 0.20 M. Calculate the initial rate, in units of 10^-3 M s^-1, when [A] = 0.50 M and [B] = 0.40 M (two decimals).

JEE Main levelNumerical answerDifficulty 2 of 3ck017

For a reaction with rate law rate $= k [A]^{2} [B]$ , the initial rate is $5.40 \times 1 0^{- 4} M s^{- 1}$ when $[A] = 0.30 M$ and $[B] = 0.20 M$ . Calculate the initial rate, in units of $1 0^{- 3} M s^{- 1}$ , when $[A] = 0.50 M$ and $[B] = 0.40 M$ (two decimals).

Numerical answer type, answer in 10^-3 M s^-1, tolerance 0.02.

Find

k

from the first set:

k = 5.40 \times 1 0^{- 4} / (0.3 0^{2} \times 0.20) = 0.0300 L^{2} mo l^{- 2} s^{- 1}

. Then rate

= 0.0300 \times 0.5 0^{2} \times 0.40 = 0.00300 M s^{- 1}

, i.e.

3.00 \times 1 0^{- 3}