Question

The rate of a reaction is directly proportional to the square of the concentration of A and inversely proportional to concentration of B. If B increases by 100%, which of the following is closest to the % change in concentration of A required to keep the rate unchanged?

Answer 1

Explanation:

Given that the rate of a reaction is directly proportional to the square of the concentration of A and inversely proportional to concentration of B.

i.e. R = rate of a reaction =
`(kA^2)/(B)`

where A shows the concentration of A and B that of B.

If B increases by 100%, then we have B to be replaced by 2B

But R is the same

i.e.
`(kA^2)/(B)=(kA_1^2)/(2B)` where new A= A1

Simplify to get

`2A^2 = A_1^2\\A_1=√(2)  A`

So A increases to sqrt of 2 times original concentration.