For a first-order reaction, the half-life period $t_{1/2}$ is related …

Question

For a first-order reaction, the half-life period $t_{1/2}$ is related to the rate constant $k$ as:

Accepted Answer

B. $t_{1/2} = \dfrac{0.693}{k}$

For a first-order reaction $k = \dfrac{2.303}{t}\log\dfrac{[A]_0}{[A]}$.
Setting $[A] = [A]_0/2$ at $t = t_{1/2}$ gives $k t_{1/2} = \ln 2 = 0.693$, hence $t_{1/2} = 0.693/k$.
Option B is the zero-order expression
option C is the second-order one.

Answer

$t_{1/2} = \dfrac{2.303}{k}$

Answer

$t_{1/2} = \dfrac{[A]_0}{2k}$

Answer

$t_{1/2} = \dfrac{1}{k[A]_0}$

For a first-order reaction, the half-life period $t_{1/2}$ is related to the rate constant $k$ as:

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