Dont understand discreet practice problem (Kaplan)

[mnmoore]

I am not sure if it is okay to post a question that kaplan has created. So if it violates any rules let me know and I will take down the post.

If you are a kaplan student and want to see the question, chapter 5 of GC, question 1

Question

In a 3rd order reaction involving 2 reactants and 2 products, doubling the concentration of the first reaction causes the rate to increase by a factor of 2. What will happen to the rate of this reaction if the concentration of the second reactant is cut in half?

Answer: it will decrease by a factor of 4.

I do not understand why this is the answer. If anyone can explain this in super simple terms I would appreciate it

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[dushash]

I am not sure if it is okay to post a question that kaplan has created. So if it violates any rules let me know and I will take down the post.

If you are a kaplan student and want to see the question, chapter 5 of GC, question 1

Question

In a 3rd order reaction involving 2 reactants and 2 products, doubling the concentration of the first reaction causes the rate to increase by a factor of 2. What will happen to the rate of this reaction if the concentration of the second reactant is cut in half?

Answer: it will decrease by a factor of 4.

I do not understand why this is the answer. If anyone can explain this in super simple terms I would appreciate it

Have you read the explanation? It explains well.
Anyway, you got 2 reactants (apple and pear). Apple has "power" of 1. Pear has "power" of 2. Thus 1+2 =3 (3rd order). If we cut pear in half (1/2) - the result will be (1/2) in power of 2 = (1/4). Probably it's more confusing. But it's easier if you write reactants with their corresponding power and simply put 1/2 instead of second reactant.