Question

In a reaction, if the concentration of reactant \( X \) is tripled, the rate of reaction becomes twenty-seven times. What is the order of the reaction?

Hint:

For determining reaction order, observe how the rate changes with concentration. If a bimolecular reaction has an excess reactant, it behaves like a first-order reaction.

Answer 1

Step 1: Determining the Order of Reaction The rate law for a reaction is generally given by: \[ \text{Rate} = k [X]^p \] Given that when \( [X] \) is tripled, the rate increases by a factor of 27: \[ 27 \times \text{Rate} = k [3X]^p \] \[ (3)^p = 27 \] Since \( 27 = 3^3 \), we get \( p = 3 \). Thus, the order of the reaction is Third order.