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.
$\begin{array}{ccccc}Sl.No& \left[A{]}_0/M\right(Initialconc.)& \left[B{]}_0/M\right(Initialconc.)& Rate/\left(Mse{c}^{-1}\right)& \\ 1.& 1.6\times {10}^{-3}& 5\times {10}^{-2}& {10}^{-3}& \\ 2.& 3.2\times {10}^{-3}& 5\times {10}^{-2}& 4\times {10}^{-3}& \\ 3.& 1.6\times {10}^{-3}& {10}^{-1}& 2\times {10}^{-3}& \\ 4.& 3.2\times {10}^{-3}& {10}^{-1}& 8\times {10}^{-3}& \end{array}$
Rate law for reaction from above data is

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

Answer 1

The correct option is B $r=k\left[A{]}^2\right[B]$

From experiment 182
Order w.r.t A = 2
From experiment 2 and 4
Order w.r.t B = 1