Consider a reaction whose slow elementary step is

CHEMISTRY · Subjective · A Level · Chemistry · Rate equations · Rate equations

Problem

A(g) + 2\,B(g) \rightarrow \text{products}

, so that

\text{rate} = k[A][B]^2

. An experiment is conducted with initial concentrations

[A]_0 = 0.10\,\text{M}

and

[B]_0 = 0.20\,\text{M}

. In a second trial,

[A]

is tripled and

[B]

is halved. By what numerical factor does the initial rate in the second trial differ from that in the first?