the reaction A->B is second order in A and the rate constant is 0.039L/mol s. if it took 23 sec for the concentration of A to decrease to 0.30 M, what was the starting concentration of A

0.41 M

Explanation:

A -> B

rate constant (k) = 0.039L/mol s

t = 23

Final concentration, [A]  = 0.30M

Initial concentration, [A]o = x

1 / [A]  = kt + 1 / [A]o

1 / [A]o = 1 / [A] - kt

1 / [A]o  = 1 / 0.30   - 0.039 (23)

1 / [A]  = 3.33 -  0.897 = 2.433

[A] = 0.41 M

1. they vary with a higher number because boiling is way hotter than melting

b is the correct answer

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