MCQ
Correct reactivity order of $S_N2$ reaction is


- ✓$(i) > (ii) > (iii)$
- B$(ii) > (iii) > (i) $
- C$(i) > (iii) > (ii)$
- D$(iii) > (i) > (ii)$

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Method $1\,:\,$ $RBr\xrightarrow[diethyl\,\,ether]{Mg}RMgBr\xrightarrow[2.\,{{H}_{3}}{{O}^{+}}]{1.\,C{{O}_{2}}}RC{{O}_{2}}H$
Method $2\,:\,$ $RBr\xrightarrow{NaCN}RCN\xrightarrow[heat]{{{H}_{2}}O,HCl}RC{{O}_{2}}H$
Which one of the following statements correctly describes this conversion ?


Here en $=$ ethylene diamine
Statement $I :$ The $E ^{\circ}$ value of $Ce ^{4+} / Ce ^{3+}$ is $+1.74 \,V$
Statement $II :$ $Ce$ is more stable in $Ce ^{4+}$ state than $Ce ^{3+}$ state.
In the light of the above statements, choose the most appropriate answer from the options given below
| $1$ | $2$ | $3$ | |
| $\mathrm{HI}\left(\mathrm{mol} \mathrm{L}^{-1}\right)$ | $0.005$ | $0.01$ | $0.02$ |
| Rate $\left(\mathrm{mol} \mathrm{L}^{-1} \mathrm{~s}-1\right)$ | $7.5 \times 10^{-4}$ | $3.0 \times 10^{-3}$ | $1.2 \times 10^{-2}$ |