What is the molecular formula of methanal?

The structural formula of benzene is:

$(a)$ Write chemical equations for the reactions of ethanoic acid with:
$(i)$ Sodium
$(ii)$ Sodium carbonate
$(iii)$ Ethanol in the presence of conc. $H_{2}SO_{4}$.
$(b)$ State the role of concentrated sulphuric acid in the esterification reaction.
$(c)$ Write one use of ethanoic acid.

Draw the structure of the simplest ketone.

Draw the possible isomers of the compound with molecular formula $C_3H_6O$ and also give their electron dot structures.

Name the functional group of the following compounds:
$(i) \ R-COOH$
$(ii) \ R-COOR'$
$(iii) \ R-OH$
$(iv) \ R-X$