If a substance has a half-life of 72.8 min, and if 65.0 g of the substance are initially present, how many grams will remain after precisely three hours?

Answer 1

A = Ao (1/2)^t/h

h is half life

t is time

Ao is original amount

A is final amount

A = 65.0 g (1/2)^180min/72.8min

A = 65.0 g(1/2)^2.47

A = 65.0 g (.1805)

A = 11.7 g