In which of the following is the carbon-halogen bond strongest?

The decreasing order of reactivity towards $S_N 1$ reaction for the following compounds is:

In which of the following reactions is the $Saytzeff$ alkene the major product?

$A$ student was carrying out a Grignard reaction between $PhMgBr$ and ethyl benzoate. She ran out of anhydrous ether just after the Grignard reagent was made. Which of the following solvents can still be used to dissolve the ethyl benzoate for its reaction with already formed $PhMgBr$?

Consider the following reaction sequence:
$Cyclohexylidene-methane$ $\xrightarrow[CH_3OH]{Br_2} A$ $\xrightarrow{KCN} B$
Identify the correct structures for $A$ and $B$ from the given options:
$A$ is:
$A) \text{ 1-(bromomethyl)-1-methoxycyclohexane}$
$B) \text{ 1-(methoxymethyl)-1-bromocyclohexane}$
$B$ is:
$C) \text{ 1-(bromomethyl)-1-methoxycyclohexane}$
$D) \text{ 1-(cyanomethyl)-1-methoxycyclohexane}$

$A$ solution of $(\pm)-2$-chloro-$2$-phenylethane in toluene is mixed slowly with a small amount of $SbCl_5$. The reaction proceeds due to the formation of: