The rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical a present and inversely proportional to the concentration of chemical b present. if the concentration of chemical b is increased by 100 percent, which of the following is closest to the percent change in the concentration of chemical a required to keep the reaction rate unchanged? a. 100% decrease b. 50% decrease c. 40% decrease d. 40% increase e. 50% increase

D. 40 % increase  

Step-by-step explanation:

r = k[A]²/[B]

The rate is inversely proportional to [B]. If [B] is doubled, the rate is halved.

We must double this rate to get back to the original.

The rate is directly proportional to [A]².

2 = [A]₂/[A]₁²     Take the square root of each side

√2 = [A]₂/[A]₁     Multiply each side by [A]₁

[A]₂ = √2[A]₁

[A]₂ = 1.41[A]₁

We must increase [A] by 41 %.

the answer is option a.

it's c (engineer's do their work with mechanical stuff not on any living being)