[cmquer]

The rate equation for the reaction between gaseous reactants A and B is: Rate= k [A]2 . If the mixture is compressed into half of its previous volume, by what factor will the rate of reaction change?

(a) Increased by a factor of 4
(b) No change
(c) Increased by a factor of 8
(d) Increased by a factor of 2

In this question, the mole ratio of A, B and the product is not given. How can I find the answer?

If there is a option of "Increased by a factor of 6", I will choose this since I found the overall reaction order is 3 in my attempt. But, am I right?

[Yggdrasil]

The mole ratio should not matter in this problem.

Is the rate equation Rate = k[A]²[ B]?  If so, think about how will compressing the mixture to half of its volume change [A] and [ B]?  You're on the right track thinking that the overall order of the reaction is 3.

[Mitch]

If you decrease the volume by 2, what does that do to the [A] term?

[hapdx]

i think in the case you mentioned above,not only the concetration of A and B will change,the rate
constant K will change either.  we may calculate it with Arrennius equation.
then the end result will not included in the answers you listed above!!!!
 

[Borek]

i think in the case you mentioned above,not only the concetration of A and B will change,the rate
constant K will change either.

There is no information about temperature changes so we are probably to assume T = const. Even if it should rise during adiabatic compression.