$2$-Phenylpropene on acidic hydration gives

On ozonolysis, one mole of a hydrocarbon produces two molecules of ethanal and one molecule of ethanedial. The hydrocarbon could be

An alkene on reductive ozonolysis gives two molecules of ${\mathrm{CH}}_2(\mathrm{CHO}{)}_2$. The alkene is

Which of the compounds with molecular formula ${\mathrm{C}}_5{\mathrm{H}}_{10}$ yields acetone on ozonolysis ?

Ozonolysis of an alkene produces only one dicarbonyl compound. The structure of the alkene is