A carbon compound ‘P’ on heating with excess cone. H2SO4 forms another carbon compound

A carbon compound ‘P’ on heating with excess cone. H2SO4 forms another carbon compound ‘Q’, which on addition of hydrogen in the presence of nickel catalyst forms a saturated carbon compound ‘R’. One molecule of ‘R’ on combustion forms two molecules of carbon dioxide and three molecules of water. Identify P, Q and R and write chemical equations for the reactions involved.

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