Final answer:
Butyl ethanoate (butyl acetate), with the structural formula CH3COO(CH2)3CH3, is an example of an open-chain ester with 4 carbons and no C-C multiple bonds.
Step-by-step explanation:
The organic molecule that is an open-chain ester containing 4 carbons and no C-C multiple bonds would be butyl ethanoate (butyl acetate), which has the structural formula CH3COO(CH2)3CH3. This ester is constructed by connecting an ethanoate (acetate) group to a butyl group.
The ethanoate group comes from acetic acid (CH3COOH), where one of the hydrogens from the hydroxyl (OH) group is replaced by a butyl group (C4H9), which is simply a chain of four carbons with hydrogen atoms filling all other bonds to complete the carbon's four bonds, creating an ester without any double or triple bonds between carbons.