From the compounds given below, number of compounds which give positive Fehling's test is _________.

Benzaldehyde, Acetaldehyde, Acetone, Acetophenone, Methanal, 4nitrobenzaldehyde, cyclohexane carbaldehyde.

The value of $$x$$ in compound 'D' is _________.

The mass of NH$$_3$$ produced when 131.8 kg of cyclohexanecarbaldehyde undergoes Tollen's test is ________ kg. (Nearest Integer)

Molar Mass of

C = 12g/mol

N = 14g/mol

O = 16g/mol

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 ____________.