Question

For a reaction $pA+qB\to \text{product}$, the rate law expression is $r=k\left[A{]}^l\right[B{]}^m$, then:

• A. $(p+l)<(l+m)$
• B. $(p+q)>(l+m)$
• C. $(p+q)$ may or may not be equal to $(l+m)$
• D. $(p+q)=(l+m)$

Answer 1

The correct option is C $(p+q)$ may or may not be equal to $(l+m)$

$p$ and $q$ are stoichiometric coefficients while $l$ and $m$ are the order of the reation with respect to $A$ and $B$ respectively. Since there is no relation between order and stoichiometric coefficient, it must be obtained experimentally. Hence, $(p+q)$ may or may not be equal to $(l+m)$.