Question

The rate constant of a zero order reaction is` 0.2 mol L^(-3) h^(-1)`. If the concentration of the reactant after 30 min is 0.05 mol ` dm^(-3)`, then its initial concentration would be
A. `0.01 "mol dm"^(-3)`
B. `0.15 "mol dm"^(-3)`
C. `0.25 "mol dm"^(-3)`
D. `4.00 "mol dm"^(-3)`

Answer 1

Correct Answer - B
For zero order reaction,
`x=kt-0.2"mol dm"^(-3)h^(-1)xx(30)/(60)h=0.1"mol dm"^(-3)`
Now, concentration `=0.05"mol dm"^(-3)`
Hence initial concentration`=0.1+0.05=0.15"mol dm"^(-3)`