Rate equations (A-level only)

The results of an investigation of the reaction between $A\text{A}$ and $B\text{B}$ are shown in this table:

Experiment	Initial $[A][\text{A}]$ / $dm−3\text{mol dm}^{-3}$	Initial $[B][\text{B}]$ / $dm−3\text{mol dm}^{-3}$	Initial rate / $s−1\text{mol dm}^{-3}\text{ s}^{-1}$
1	0.300	0.400	0.180
2	To be calculated	0.800	0.720

The rate equation is: $rate=k[A]2[B]\text{rate} = k [\text{A}]^2 [\text{B}]$

What is the initial concentration of $A\text{A}$ in experiment 2?

$0.212$

$0.300$

$0.424$

$0.600$

Rate equations (A-level only) Questions

The results of an investigation of the reaction between $A\text{A}$ and $B\text{B}$ are shown in this table:

Experiment	Initial $[A][\text{A}]$ / $dm−3\text{mol dm}^{-3}$	Initial $[B][\text{B}]$ / $dm−3\text{mol dm}^{-3}$	Initial rate / $s−1\text{mol dm}^{-3}\text{ s}^{-1}$
1	0.300	0.400	0.180
2	To be calculated	0.800	0.720

The rate equation is: $rate=k[A]2[B]\text{rate} = k [\text{A}]^2 [\text{B}]$

What is the initial concentration of $A\text{A}$ in experiment 2?

$0.212$

$0.300$

$0.424$

$0.600$