Question

Consider two first order reactions (1) and (2). The graph of $\log [A{]}_t$ vs $t$ for the two reactions is shown in figure. Choose the correct relation between half life of the first reaction, ${\left(t_{1/2}\right)}_1$ and that of the second reaction, ${\left(t_{1/2}\right)}_2$.

• A. ${\left(t_{1/2}\right)}_1<{\left(t_{1/2}\right)}_2$
• B. ${\left(t_{1/2}\right)}_1>{\left(t_{1/2}\right)}_2$
• C. ${\left(t_{1/2}\right)}_1={\left(t_{1/2}\right)}_2$
• D. None of these

Answer 1

Answer: (A)

For (i) reaction slope is less than the slope of reaction (ii) hence $k_1>k_2$ and ${\left(t_{1/2}\right)}_1<{\left(t_{1/2}\right)}_2$.