What is the molecular formula for ethene?

The IUPAC name of the following compound is:

When water gas is mixed with half its volume of hydrogen and the mixture is compressed 300 atmospheric pressure and passed over $\mathrm{ZnO}.{\mathrm{Cr}}_2{\mathrm{O}}_3$ catalyst a colourless liquid is obtained which is used as a solvent for paint and varnishes. The liquid will be 

According to the IUPAC system which type of compound is shown by the given structure:

IUPAC name of the following compound will be

Complete the following table which relates to the homologous series of hydrocarbons.

Which of the following is the ketone functional group, $\mathrm{R}=(-{\mathrm{CH}}_3)$, $\mathrm{R}$ is Alkyl group.