The molecularity of a reaction is:

May be the same or different as compared to the order

The answer is (4) May be the same or different as compared to the order.

The molecularity of a reaction may be the same or different as compared to its order.

The molecularity of a reaction is the number of molecules that collide simultaneously to bring about a chemical reaction. The order of a reaction is the sum of the exponents in the rate law equation.

For example, the reaction

\(H_2 + I_2 → 2HI\)

is a bimolecular reaction because it involves the simultaneous collision of two molecules (\(H_2\) and \(I_2\)). The rate law for this reaction is:

\(\text{rate = }k[H_2][I_2]\)

Where, k is the rate constant. The order of this reaction is 2 because the rate law contains the square of the concentration of \(H_2\) and the concentration of \(I_2\).

Another example is the reaction

\(CH_3CHO → CH_4 + CO\),

which is a unimolecular reaction because it involves the simultaneous collision of one molecule \((CH_3CHO)\). The rate law for this reaction is:

\(\text{rate = }k[CH_3CHO]\)

Where, k is the rate constant. The order of this reaction is 1 because the rate law contains only the concentration of \(CH_3CHO\).

As you can see, the molecularity of a reaction does not always have to be the same as its order. In fact, they can be different.