Which from following is a correct priority order for selection of principal functional group for nomenclature of polyfunctional compound?

Which of the following is used to avoid leakage of electrolyte in dry cell?

Identify the polymer used to obtain LCD screen from following.

Identify the product X in the following reaction.

Sodium propanoate $\xrightarrow[\Delta]{\text { soda-lime }} \mathrm{X}+$ sodium carbonate