a concentration-time study of the gas phase reaction a 2A3 -> 3A2 produced the data in the table below.

Question

Time (s) [A3] (M) [A2] (M)

0 4.00 × 10–4 0
10 2.00 × 10–4 3.00 × 10–4
20 1.00 × 10–4 4.50 × 10–4
30 5.00 × 10–5

A) What is the concentration of A2 in the time interval 20-30 seconds?
I got 7.50 x 10^-6

B) What is the concentration of A2 after 30 seconds?

Answer 1

I got 5.00 x 10^-5