$CH_3MgBr + CO_2$ $\xrightarrow{\text{Dry ether}} Y$ $\xrightarrow{H_3O^{\oplus}} Z$
Identify $Z$ from the following.

What will be the final product of the following reaction sequence?
$CH \equiv CH$ $\xrightarrow{CH_3MgBr}$ $\xrightarrow{CO_2/H_3O^+}$ $\xrightarrow{HgSO_4/H_2SO_4}$ $\xrightarrow{Ag_2O, \Delta} ?$

Which of the following sequences of reagents is used to convert $R-CH_2-CH_2-OH$ into $R-CH_2-CH_2-COOH$?

The major product in the following reaction is:

The product obtained when acetic acid is treated with phosphorus trichloride is

Acetic acid is manufactured by the fermentation of