CH3CH2CH2COOCH2CH3

Breakdown:

* CH3CH2CH2CO represents the butanoic acid part.

* OCH2CH3 represents the ethyl ester part.

Visual Representation:

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O

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CH3CH2CH2C - O - CH2CH3

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Explanation:

* Butanoic acid is a carboxylic acid with four carbon atoms.

* Ethyl ester is formed when the -OH group of butanoic acid is replaced by an ethoxy group (-OCH2CH3).

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