For the reaction 2 A + 4 B → 2 C + 4 D, what is the absolute magnitude of the rate of change for [B] when [C] is increasing at 3.2 M/s?

Question

This is for General Chemistry 2.

Answer 1

2A + 4B ==> 2C + 4D

If C is increasing at 3.2 M/s, then B will be decreasing at twice that rate because it take 4 of B to make 2 of C. So absolute magnitude of the rate of change for B would be 2 x 3.2 M/s = 6.4 M/s.

Another way to view this is...

-1/4 ∆B/∆T = + 1/2 ∆C/∆T

-1/4 B = 1/2 3.2

-1/4 B = 1.6

B = 6.4 M/s