Question

The rate constant of the reaction $A\to Bis0.6\times {10}^{-3}mol{L}^{-1}{s}^{-1}$. If the concentration of A is 5 M, then concentration of B after 20 minutes is

• A. 3.60 M
• B. 0.36 M
• C. 0.72 M
• D. 1.08 M

Answer 1

The correct option is C 0.72 M

Order of reaction is zero as unit of rate constant is mole per second.
$\therefore K=\frac{[A{]}_0-[A]}{t}\Rightarrow 0.6\times {10}^{-3}=\frac{5-\left[A\right]}{20\times 60}\therefore \left[A\right]=5-0.72$
$\therefore$ Concentration of B after 20 minutes is .72 M.