Question

Which of the following expression are correct for a first-order reaction with the rate constant 'k' initial concentration 'a' and half-life $t_{\frac{1}{2}}$?

• A. $t_{\frac{1}{2}}=\frac{In2}{k}$
• B. $k\alpha a$
• C. $k=\frac{2.303}{t_{\frac{1}{2}}}log2$
• D. $t_{\frac{1}{2}}=\frac{1}{k\times a}$

Answer 1

Answer: (A), (C)

$k=\frac{2.303}{t_{\frac{1}{2}}}log2$
$t_{\frac{1}{2}}=\frac{In2}{k}$

For $1^{st}$ order reaction $t_{\frac{1}{2}}=\frac{2.303}{k}log\frac{[A{]}_0}{[A{]}_0/2}$