Aldehydes Ketones And Carboxylic Acids

Number of isomeric compounds with molecular formula \(\mathrm{C}_{9} \mathrm{H}_{10} \mathrm{O}\) which (i) do not dissolve in \(\mathrm{NaOH}\) (ii) do not dissolve in \(\mathrm{HCl}\). (iii) do not give orange precipitate with 2,4-DNP (iv) on hydrogenation give identical compound with molecular formula \(\mathrm{C}_{9} \mathrm{H}_{12} \mathrm{O}\) is ____________.