Alcohols, Phenols, and Ethers — Chemistry STD 12 Science — Question

$\begin{matrix}
   \begin{matrix}
   \,\,\,\,\,C{{H}_{3}}  \\
   |  \\
\end{matrix}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,  \\
   C{{H}_{3}}-C-C{{H}_{2}}C{{H}_{2}}OH  \\
   |\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,  \\
   C{{H}_{3}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,  \\
\end{matrix}$ $\xrightarrow[{{H_2}O,heat}]{{{K_2}C{r_2}{O_7};{H_2}S{O_4}}}A$ $\xrightarrow{{SOC{l_2}}}B\xrightarrow[{(2{\kern 1pt} mole)}]{{{{(C{H_3})}_2}NH}}C$ $\xrightarrow[{2.{\kern 1pt} {H_2}O}]{{\begin{array}{*{20}{c}}
  {1.{\kern 1pt} LiAl{H_4}} \\ 
  {diethyl{\kern 1pt} {\kern 1pt} ether} 
\end{array}}}D$

$(i)\,\,$on doubling the initial concentration of $A$ only, the rate of reaction is also doubled and

$(ii)$  on doubling the initial concentration of both $A$ and $B,$ there is a change by a factor of $8$ in the rate of the reaction.

The rate of this reaction is given by

Reason : It has a plane of symmetry.