Question

For the given zero order reaction:
$A\to P$ The initial concentration of the reactant is $0.35mol/L$ and it reduces to half in $5min$. Calculate the rate constant

• A. $1.75mol{L}^{-1}mi{n}^{-1}$
• B. $3.5mol{L}^{-1}mi{n}^{-1}$
• C. $0.175mol{L}^{-1}mi{n}^{-1}$
• D. $0.035mol{L}^{-1}mi{n}^{-1}$

Answer 1

The correct option is D $0.035mol{L}^{-1}mi{n}^{-1}$

For a zero order reaction:
$\text{Rate}\left(r\right)=k[A{]}^0=-\frac{d\left[A\right]}{dt}$
Since the initial concentration reduces to half in $5min$
Half life:
$t_{1/2}=5min$
For a zero order reaction:
$t_{1/2}=\frac{\left[A_0\right]}{2k}5=\frac{0.35}{2\times k}k=0.035mol{L}^{-1}mi{n}^{-1}$