Describe a chemical test to confirm the presence of a carbonyl group. How could the product of this test be used to identify the specific carbonyl compound? Your answer should not include spectroscopy.

Describe a chemical test that would identify whether a carbonyl compound is an aldehyde. Your answer should include the reagent and observations.

A student is provided with two unknown carbonyl compounds, F and G.

The compounds are analysed and found to have identical percentage compositions by mass: $C:66.67\%$; $H:11.11\%$; $O:22.22\%$

The mass spectra of the two compounds show the following key features:

• Compound F has a molecular ion peak at $m/z=72$ and a significant fragment peak at $m/z=29$.
• Compound G has a molecular ion peak at $m/z=72$ and a significant fragment peak at $m/z=43$.

Use this information to identify the structures of the two compounds. Include relevant fragment ions present in the mass spectrum of each compound and draw their structures.

The organic compound H contains carbon, hydrogen, and oxygen only and has an $M_r$ of $114.0$. Compound H has two carbonyl groups and no other functional groups.

The ${}^{1}H$ NMR spectrum of organic compound H shows:

• A multiplet (quartet) centred at $\delta =3.8ppm$ (relative peak area = 1)
• A singlet at $\delta =2.1ppm$ (relative peak area = 6)
• A doublet at $\delta =1.4ppm$ (relative peak area = 3)

Analyse the spectrum to suggest a possible structure for compound H. Show all your reasoning.