Question
What is the difference between order of a reaction and its molecularity?
| Order of Reaction | Molecularity of a Reaction |
| 1. It is the sum of the concentration terms on which the rate of reaction actually depends or it is the sum of the exponents of the concentrations in rate law equation. | 1. It is the number of atoms, ions or molecules that must collide with one another simultan-eously so as to result into a chemical reaction. |
| 2. It need not be a whole number i.e., it can be fractional as well as zero. | 2. It is always a whole number. |
| 3. It can be determined experimentally only and cannot be calculated. | 3. It can be calculated by simply adding the molecules of the slowest step. |
| 4. It is for the overall reaction and no separate steps are written to obtain it. | 4. The overall mole-cularity of a complex reaction has no signi-ficance. It is only the slowest step whose molecularity has signi-ficance for the overall reaction. |
| 5. Even the order of a simple reaction may not be equal to the number of molecules of the reactant is as seen from the balanced equation. | 5. For simple reactions, the molecularity can usually be obtained from the stoichiometry of the equation. |
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
|
|
Column $I$
|
|
Column $II$
|
| $i.$ |
Lead storage battery
|
$a.$ |
Maximum efficiency.
|
| $ii.$ |
Mercury cell
|
$b.$ |
Prevented by galvanisation.
|
| $iii.$ |
Fuel cell
|
$c.$ |
Gives steady potential.
|
| $iv.$ |
Rusting
|
$d.$ |
$Pb$ is anode, $PbO_2$ is cathode.
|