Identify $A$ and $B$ in the following reaction:

The boiling point of ethyl alcohol should be less than that of:

When formic acid is heated with conc. $H_{2}SO_{4}$,the gas evolved is

When carboxylic acid reacts with organolithium reagents to give ketones,side reactions sometimes occur. For example,
$HOCH_2CH_2CH(CH_3)CH_2CH_2COOH$ $\xrightarrow[(x) \, CH_3Li]{tetrahydro\,furan}$ $\xrightarrow[NH_4Cl]{H_2O}$ $\underset{63\%}{\text{Compound } A: HOCH_2CH_2CH(CH_3)CH_2CH_2COCH_3}$ + $\underset{37\%}{\text{Compound } (B)}$
The value of $(x)$ in the above reaction is:

In the following reaction sequence,identify product $Q$ and reagent $R$:

Formaldehyde and formic acid can be distinguished using