Aldehydes and ketones are both carbonyl compounds, which means they contain a carbon-oxygen double bond C=O . The primary structural difference between them lies in the groups attached to the carbonyl carbon.In aldehydes, the carbonyl carbon is bonded to a hydrogen atom and an alkyl or aryl group R . The general structure of an aldehyde is R-CHO. In ketones, the carbonyl carbon is bonded to two alkyl or aryl groups R1 and R2 . The general structure of a ketone is R1-CO-R2.The differences in structure between aldehydes and ketones affect their reactivity towards nucleophiles such as water and ammonia. Nucleophiles are species that donate an electron pair to an electrophile, forming a new bond. In carbonyl compounds, the carbonyl carbon is electrophilic due to the polarization of the C=O bond, which results from the higher electronegativity of oxygen compared to carbon.Aldehydes are generally more reactive towards nucleophiles than ketones. This increased reactivity can be attributed to two factors:1. Steric hindrance: Aldehydes have a hydrogen atom bonded to the carbonyl carbon, which is smaller than the alkyl or aryl groups bonded to the carbonyl carbon in ketones. This means that there is less steric hindrance in aldehydes, allowing nucleophiles to approach the carbonyl carbon more easily.2. Electron-donating effect: In ketones, the two alkyl or aryl groups bonded to the carbonyl carbon can donate electrons through the inductive effect, which slightly reduces the positive charge on the carbonyl carbon. In aldehydes, there is only one alkyl or aryl group, and the other substituent is a hydrogen atom, which does not have an electron-donating effect. As a result, the carbonyl carbon in aldehydes carries a greater partial positive charge, making it more susceptible to nucleophilic attack.When reacting with water H2O or ammonia NH3 , aldehydes and ketones can form hydrates geminal diols and imines, respectively. Due to their higher reactivity, aldehydes generally form these products more readily than ketones. However, the stability of these products can also be influenced by other factors, such as the presence of electron-donating or electron-withdrawing groups on the carbonyl compound.