Question

Statement 1: Half-life period of a reaction of first order is independent of initial concentration
Statement 2:Half-life period for a first order reaction $t_{1/2}=\frac{2.303}{K}log\, 2$

• A. If both Statement 1 and Statement 2 are true and the statement 2 is the correct explanation of the statement 1.
• B. If both Statement 1 and Statement 2 are true but statement 2 is not the correct explanation of the statement 1.
• C. If Statement 1 is true but Statement 2 is false.
• D. If Statement 1 is false but Statement 2 is true.

Answer 1

Answer: (A)

For a first order reaction $K=\frac{2.303}{t}log \frac{a}{a-x}$ where a is initial concentration, and $x$ is the amount reacted in time $t$ For half-life $x=a/2, t=t_{1/2}$
$K=\frac{2.303}{K}log \frac{a}{a-a/2}$
$t_{1/2}=\frac{2.303}{K}log 2=\frac{0.693}{K}$