Given that, P→Q is a zero order reaction. Initial concentration, [A]0=0.1M Final concentration, [A]t=0.05M Time taken, t=10s For, zero order reaction, k=
[A]0−[A]t
t
=
0.1−0.05
10
=0.005Ms−1 Now, for concentration of P after 15 seconds, 0.005=