Question

Suppose a compound is involved in three
different reactions denoted R1, R2, and R3.
Tripling the concentration of this reactant in
all three reactions causes the rates of reaction
to increase by factors of 3, 9, and 1, respec-
tively. What is the order of each reaction with
respect to this reactant?
>>> I'm trying to make a guess because I don't understand. My guess is 1, 2, 0.

Answer 1

I think you are correct. For the first one,
R1 = k(A)^x but we can ignore k since it will be a constant.
logR1 = x*log(A)
If A is tripled, then R1 is 3R1
log 3 = x*log 3
0.477 = x*0.477 and
x = 1 so that is first order.

If A is tripled, then R1 = 9R1
log 9 = x*log 9
0.954 = x*0.477
x = 0.954/0.477 = 2 or second order.

If A is tripled, then R1 = 1*R1
log 1 = x*log3
0 = x*0.477
x = 0/0.477 = 0 = zero order.