Question

For the reaction $A\to B$ the rate law is, rate $=k\left[A\right]$. Which of the following statement is incorrect?

• A. The reaction follows first order kinetics
• B. The $t_{\frac{1}{2}}$ of reaction depends upon initial concentration of reactants
• C. k is constant for the reaction at a constant temperature
• D. The rate law provides a simple way of predicting the concentration of reactants and products at any time after the start of the reaction

Answer 1

The correct option is B The $t_{\frac{1}{2}}$ of reaction depends upon initial concentration of reactants

For first order,
$k=\frac{1}{t}ln\left[\frac{a}{a-x}\right]$

$t_{1/2}=\frac{ln2}{k}$

$\therefore t_{1/2}=\frac{0.693}{k}$

So it is independent of concentration.