The reaction shown has first order kinetics:

2H2 O2 (1) —> 2H2 O (1) + O2 (g)

If originally a solution of 0.600 M H2O2, its concentration was found to be 0.0750 M after 54.0 min.

In how many minutes will the concentration be 0.300M?

A) 6.80

B) 18.0

C) 14.0

D) 28.0 E) 54.0