Question

Consider the rate law below. R=k(NO2)^2 what happens to the rate if the concentration is tripled?

The rate increases by a factor of 9.
The rate decreases by a factor of 6.
The rate triples.
The rate doubles.

Answer 1

For this case we have the following equation:
R = k (NO2) ^ 2
if the concentration is tripled, we must rewrite the equation.
We have then:
R '= k (3 * NO2) ^ 2
R '= 9 * k (NO2) ^ 2
Rewriting:
R '= 9 * R
Answer:
The rate increases by a factor of 9.