What is the bond length between carbon and bromine in $CH_3Br$ molecule (in $pm$)?

The major product of the following reaction is:
$C_6H_5-CH_2-C(Br)(CH_3)-CH_2-CH_3 \xrightarrow[C_2H_5OH]{C_2H_5ONa}$

Consider the following groups:
$I$. $-OAc$
$II$. $-OMe$
$III$. $-OSO_2Me$
$IV$. $-OSO_2CF_3$
The order of leaving power is:

Which of the following chiral compounds undergoes nucleophilic substitution by $OH^-$ ions to form a racemic mixture?
$(a)$ $CH_3-CH(Br)-C_2H_5$
$(b)$ $CH_3-C(Br)(CH_3)-C_2H_5$
$(c)$ $CH_3-CH(C_2H_5)-CH_2Br$

Which alkyl halide undergoes the ${S}_{N}1$ reaction most rapidly?

Which of the following halides undergoes hydrolysis most rapidly?