Question

The rate constant of a zero order reaction is $0.2mold{m}^{-3}{h}^{-1}$. If the concentration of the reactant after 30 minutes is $0.05mold{m}^{-3}$. Then its initial concentration would be:

• A. $0.15mold{m}^{-3}$
• B. $1.05mold{m}^{-3}$
• C. $0.25mold{m}^{-3}$
• D. $4,00mold{m}^{-3}$

Answer 1

The correct option is A $0.15mold{m}^{-3}$

For a zero order reaction,

$t=\frac{\left[A_0\right]-\left[A\right]}{k}$

$t=30min=\frac{1}{2}hr$

$k=0.2mold{m}^{-3}{h}^{-1}$

$\left[A\right]=0.05mold{m}^{-3}$

On putting these values in the equation above, we get $A_o=0.15mold{m}^{-3}$