Question

For a given reaction:
$aA+bB+cC\to \text{Products}$
Here $a,b,c\text{are the stoichiometric coefficients}$
Choose the correct option:

• A. The overall order of reaction is always equal to $(a+b+c)$
• B. Order of reaction w.r.t. to reactant A may or may not be equal to $a$
• C. Order of reaction w.r.t. to reactant B is always equal to $b$
• D. Order of reaction w.r.t. any reactant is always equal to $(a+b+c)$

Answer 1

The correct option is B Order of reaction w.r.t. to reactant A may or may not be equal to $a$

For a given reaction:
$aA+bB+cC\to \text{Products}$
By experiment,Rate of reaction (r):

$r\propto \left[A{]}^x\right[B{]}^y[C{]}^z$
Overall order of the reaction is :
$(x+y+z)$
$x:\text{Order w.r.t reactant A}$
$y:\text{Order w.r.t reactant B}$
$z:\text{Order w.r.t reactant C}$
Here ,
$x,y,z\text{are experimentally determined quantities}$
$x\text{may or may not be equal to}a$
$y\text{may or may not be equal to}b$
$z\text{may or may not be equal to}c$

So, overall order may or may not be equal to (a+b+c)