ROH - Alkanols

R\(_2\)CO - Ketones

RCOOR\(^1\) - Esters or alkanoates

The general formula for alkanals is C\(_n\)H\(_{2n+1}\)CHO, where n = 0, 1, 2, 3, and so on.  In other words, it is RCHO

Alkanals are compounds that are formed when long-chain primary alcohols are oxidized. Primary alkylsulphates biodegrade to produce these alcohols.