Question

Consider the following elementary reaction,
$2A+B+C\to Products$.
All reactant are present in the gaseous state and reactant C is taken in excess.
What is the rate expression of the reaction?

• A. $Rate=k\left[A{]}^2\right[B\left]\right[C]$
• B. $Rate=k\left[A{]}^2\right[B]$
• C. $Rate=k\frac{\left[A{]}^2\right[B]}{\left[C\right]}$
• D. $Rate=k[C{]}^0$

Answer 1

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

Since C is taken in excess, so its concentration does not change. So it is not taken in rate expression of the reaction.
and rate law is,
$Rate=k\left[A{]}^2\right[B]$