Question

For an elementary reaction 2A+B${}_{\left(\text{excess}\right)}$+C$\to$ products on increasing the concentration of A three times, of B two times and of C two times, the effect on the rate of reaction is:

• A. Rate of reaction increases by 4 times
• B. Rate of reaction decreases by 12 times
• C. Rate of reaction increases by 6 times
• D. Rate of reaction increases by 18 times

Answer 1

The correct option is D Rate of reaction increases by 18 times

$2A+B\left(exess\right)+C\to$ produef

Rate of reaction $=k\left[A{]}^2\right[C{]}^1$

As we increase concentration of $A$ & $C$ are $3$ times and $2$ times respectively. Then

$R=k\left[3A{]}^2\right[2C{]}^2$

$=k9A^{2}2\left[C\right]$

$=18k\left[A{]}^2\right[C{]}^2$

Note: As $B$ in excess so concentration of $B$ alone of effect on Rate of reaction.

So Rate Increases as $18$ times.