Question

The rate constant of a reaction A + 2B $\longrightarrow$ Product is expressed by the equation $R = [A][B]^2$. The molecularity of reaction will be:

• A. 2
• B. 3
• C. 5
• D. 6

Hint:

Molecularity is always a whole number and is determined by adding the number of reactant species in an elementary reaction step.

Answer 1

The Correct Option is B

Step 1: Understanding molecularity.
Molecularity of a reaction is defined as the total number of reacting species (molecules, atoms, or ions) taking part in the elementary step of the reaction.

Step 2: Reaction given.
\[ A + 2B \longrightarrow \text{Product} \] This means 1 molecule of A and 2 molecules of B participate in the reaction.

Step 3: Calculate molecularity.
Total number of species involved = $1 + 2 = 3$.

Step 4: Conclusion.
Hence, the molecularity of this reaction is 3.

Final Answer: \[ \boxed{3} \]