Question

For a chemical reaction $t_{1/2}$ is 2.5 hours at room temperature. How much of the reactant will be left after 7.5 hours if initial weight of reactant was 160 gm?
(a) 10 gm
(b) 40 gm
(c) 80 gm
(d) 20 gm

Answer 1

I don't know the answer