The reaction between propanal an aldehyde and sodium hydroxide a strong base in the presence of water is a nucleophilic addition reaction. The mechanism proceeds as follows:1. Nucleophilic attack: The hydroxide ion OH- from sodium hydroxide acts as a nucleophile and attacks the electrophilic carbonyl carbon of propanal. This results in the formation of an alkoxide intermediate and the breaking of the pi bond between the carbonyl carbon and oxygen.2. Protonation: The alkoxide intermediate abstracts a proton H+ from a water molecule, resulting in the formation of an alcohol.The final products of this reaction are sodium ions Na+ and the corresponding alcohol, which is 1-propanol.Here's the balanced equation for the reaction:Propanal CH3CH2CHO + NaOH aq 1-Propanol CH3CH2CH2OH + Na+ aq