Question

Multiple choice-- please help!

Study the chemical reaction.

A ⟶ B + C

This reaction is second order in A.

What is the rate law for this reaction?

Rate = K [B][C]^2
Rate = K [A]^2

Answer 1

The rate law for the reaction : r=k.[A]²

Further explanation

Given

Reaction

A ⟶ B + C

Required

The rate law

Solution

The rate law is a chemical equation that shows the relationship between reaction rate and the concentration / pressure of the reactants

For the second-order reaction it can be:

1. the square of the concentration of one reactant.

`\tt r=k[A]^2`

2. the product of the concentrations of two reactants.

`\tt r=k[A][B]`

And the reaction should be(for second order) :

2A ⟶ B + C

Thus, for reaction above (reactant consumption rate) :

`\tt r=-(\Delta A)/(2\Delta t)=k[A]^2`