Question

For the reaction $A+B\to C$ ; starting with different initial concentration of $A$ and $B$ , initial rate of reaction were determined graphically in four experiments.
$3.2\times 10^{-3}$

S.NO.	$[A{]}_0/M$ (Initial conc.)	$[B{]}_0/M$ (Initial conc.)	$rate/M{\sec }^{-1}$
$1$	$1.6\times 10-3$	$5\times 10-2$	$10-3$
$2$	$3.2\times 10-3$	$5\times 10-2$	$4\times 10-3$
$3$	$1.6\times 10-3$	$10-1$	$2\times 10-3$
$4$	$3.2\times 10^{-3}$	$10^{-1}$	$8\times 10^{-3}$

Rate law for reaction from above data is

• A. $r=k[A{]}^2[B{]}^2$
• B. $r=k[A{]}^2[B]$
• C. $r=k[A][B{]}^2$
• D. $r=k[A][B]$

Answer 1

Answer: (B)

$R=K[A{]}^m[B{]}^n$
$10^{-3}=K{\left(1.6\times 10^{-3}\right)}^m{\left(5\times 10^{-2}\right)}^n$
$3.2\times 10^{-3}=K{\left(3.2\times 10^{-3}\right)}^m{\left(5\times 10^{-2}\right)}^n$
$1.6\times 10^{-3}=K{\left(10^{-1}\right)}^m{\left(2\times 10^{-3}\right)}^n$
$3.2\times 10^{-3}=K{\left(10^{-1}\right)}^m{\left(8\times 10^{-3}\right)}^n$
Solving $R=K[A{]}^2[B]$