Identify the product formed in the following reaction.
$CH_3CH_2MgBr \xrightarrow[\text{ii) dil. } HCl]{\text{i) Dry ice / dry ether}} \text{Product}$

$RMgX + CO_2$ $\xrightarrow[\text{dry}]{ \text{ether} } Y$ $\xrightarrow{ H_3O^{+} } RCOOH$
What is $Y$ in the above reaction?

$Ph-C(=O)-CH_3$ $\xrightarrow[HCl]{NaNO_2} (A)$ $\xrightarrow[heat]{Ac_2O} (B)$ $\xrightarrow{H_3O^{+}} (C)$
Product $(C)$ of the above reaction is

Write the method of preparation of carboxylic acid compounds from ester compounds,with suitable examples.

Which of the following would be the best synthesis of $2,2-$dimethylpropanoic acid?

Compare the two methods shown for the preparation of carboxylic acids.
Method $1$: $RBr$ $\xrightarrow[diethyl \ ether]{Mg} RMgBr$ $\xrightarrow[2. \ H_3O^{+}]{1. \ CO_2} RCO_2H$
Method $2$: $RBr$ $\xrightarrow{NaCN} RCN$ $\xrightarrow[heat]{H_2O, HCl} RCO_2H$
Which one of the following statements correctly describes this conversion for the given substrate ($1$-bromoadamantane)?