How many organic products will be formed when the following compound undergoes decarboxylation?
(Image: $A$ substituted cyclopentane ring with two $-COOH$ groups at the same carbon atom,and two $-CH_3$ groups at adjacent carbons.)

An optically active compound $'X'$ having molecular formula $C_4H_8O_3$ evolves $CO_2$ with $NaHCO_3$. $'X'$ on treatment with $LiAlH_4$ gives an achiral compound. Then $'X'$ is:

The reagent which does not give acid chloride on treating with a carboxylic acid is

What is formed when oxalic acid is dehydrated with concentrated $H_2SO_4$?

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:

Propionic acid with $Br_2/P$ yields a dibromo product. Its structure would be: