Tischenko reaction is a modification of

The reactant is $3$-methylpentanal. The reaction with $NaCN$ followed by $H_2SO_4$ (cyanohydrin formation) is shown below:
$CH_3CH_2CH(CH_3)CH_2CHO \xrightarrow{NaCN/H^+} CH_3CH_2CH(CH_3)CH_2CH(OH)CN$
Products of the reaction are:

Which of the following compounds will not give "Iodoform" by reaction with "Sodium hypoiodite"?

Among the following,the order of reactivity towards nucleophilic addition is:

$3$-hydroxybutanal is formed when $(X)$ reacts with $(Y)$ in dilute $(Z)$ solution. What are $X, Y$ and $Z$?

Identify the reagents $X$ and $Y$ in the following reaction sequence:
$CH_3COCl \xrightarrow{X} CH_3CH_2OH$
$CH_3COCl \xrightarrow{Y} CH_3CHO$