Question

Which of the following plot(s) is/are correct for a first order reaction?

• A. I, II
• B. II, I
• C. I, II, III
• D. I, III

Answer 1

The correct option is C I, II, III

Let consider the following reaction is first order reaction.
$A\to B$
$t=0a0$
$ta-xx$
On applying integrated equation ,we get expression as
$ln\frac{a}{a-x}=kt$
$log\frac{a}{a-x}=\frac{1}{2.303}k\times t\left(1\right)$
As linear equation $y=mx+c$
if we expand equation (1) then we get
$log(a-x)=log\left(a\right)-kt$
As linear equation $y=mx+c$ ,we get
Half life of first order reaction $t_{\frac{1}{2}}=\frac{0.693}{k}$
which is independent of time factor so magnitude of half life is constant with respect to time .