Question 7A.11 Textbook

[705960769]

For part B the question asks what the factor be of the reaction rate if the concentration of H2 is doubled and the answer says it is a factor of 2. I am just confused because the question said that the reaction is a second-order reaction and I know the reaction rate is proportional to the square of one of the concentrations. So why is the factor not 4?

[Mia Chem14B]

doubling the concentration of A leads to a factor of 4 increase in the reaction rate, not 2

[Taryn 1J]

This reaction is indeed a 2nd-order process however it is important to read the note that tells us that it's a first-order process in each reactant (since there are two reactants, you add the orders together for the overall order of the reaction). Therefore, doubling the concentration of just one of the reactants (a first-order process) would result in a doubling of reaction rate.