Which of the following compounds is the strongest acid?

$C_2H_5OH + 4I_2 + 3Na_2CO_3 \longrightarrow X + HCOONa + 5NaI + 3CO_2 + 2H_2O$
In the above reaction,'$X$' is

Explain the effect of an increase in the number of carbon atoms and branching on the boiling points of alcohols and phenols.

Nitroglycerine is

The correct order of decreasing reactivity towards $H_3PO_4$ for the following compounds is:

When a Grignard reagent reacts with $(B)$,product $(D)$ is obtained. Reactant $(A)$ of the above reaction is:
$(A)$ $\xrightarrow{PBr_3} (C)$ $\xrightarrow{Mg, \text{ether}} \text{Grignard reagent}$
$(A) \xrightarrow{Na_2Cr_2O_7, H_2SO_4} (B)$
$\text{Grignard reagent} + (B) \to (D) \xrightarrow{H_3O^\oplus} (3,4-\text{dimethylhexan-3-ol})$