Question

For a reaction of type $A+B\to$ Products, it is observed that doubling the concenlcration of A causes the reaction rate to be four times, but doubling the amount of B does not affect the rate. The rate of reaction is

• A. Rate $=k[A][B]$
• B. Rate $=k/4[A{]}^2$
• C. Rate$=k[A{]}^2[B{]}^0$
• D. Rate $=k[A{]}^2[B{]}^2$

Answer 1

Answer: (C)

Let rate of reaction be,
$r=K[A{]}^x[B{]}^y\dots (i)$
When concentration of A is doubled, rate becomes four times
$\therefore 4r=K[2A{]}^x[B{]}^y\dots (ii)$
when concentration of B is doubled, rate is not affected
$\therefore r=K[A{]}^x[2B{]}^y\dots (iii)$
on dividing (ii) by (i), $x=2$ and on dividing (iii) by (i) $y=0$
$\therefore$ Rate $=k[A{]}^2[B{]}^0$