Question

The rate constant of a zero order reaction is 0.2 mol $d{m}^{-3}{h}^{-1}$. If the concentration of the reactant after 30 minutes is 0.5 mol $d{m}^{-3}$. Then its initial concentration would be :-

• A. 0.60 mol $d{m}^{-3}$
• B. 4.00 mol $d{m}^{-3}$
• C. 0.25 mol $d{m}^{-3}$
• D. 0.15 mol $d{m}^{-3}$

Answer 1

Answer: (A)

The correct option is A 0.60 mol $d{m}^{-3}$
For zero order reaction : $C_t$ = $C_o$ - kt

$C_o$ : initial concentration

$C_t$ : concentration at time "t"

k : rate constant of reaction.

t : convert time in hours as rate constant is in hours

So , $0.5=$ $C_o$ $-\left(30/60\right)\times 0.2$

$C_o$ = 0.6 .

Initial concentration is 0.6 .