Question Video: Identifying the Product of the Reaction of H₃CCOOH and CH₃CH₂OH in the Presence of H₂SO₄ in a set of Displayed Formulas Chemistry

Video Transcript

Consider the following reaction. Which of the following products is produced from the reaction?

Let’s begin by examining the given reaction. The first reactant is a carboxylic acid. We can tell from the structural formula that this molecule is a carboxylic acid because it contains the carboxyl group. The name of this carboxylic acid is ethanoic acid. Let’s look closely at the name. The eth- portion of the name indicates there are two carbon atoms in the carbon chain. The -an- part of the name indicates that there are single bonds between the carbon atoms in the chain. And the suffix -oic and the word “acid” are added to the name of the carbon chain when naming any carboxylic acid.

The second reactant in the reaction is an alcohol. We can identify this molecule as an alcohol because of the presence of the hydroxy group. Like all alcohols, the oxygen atom of the hydroxy group is connected to the carbon base chain of the alcohol by a single bond. The name of this alcohol is ethanol. The eth- part of the name indicates that there are two carbon atoms in the carbon chain, while the -an- part tells us that there are single bonds between the two carbon atoms in the chain. Finally, the suffix -ol is added to an alcohol with one hydroxy group.

In the reaction, an acid catalyst, H2SO4, is used. When a carboxylic acid reacts with an alcohol in the presence of an acid catalyst, the products are an ester and water. The reaction is known as acid-catalyzed esterification of a carboxylic acid. The reaction is reversible, but we will ignore that for the purpose of this video.

To solve this problem, we need to determine which of the structural formulas given in the answer choices is the ester formed by the reaction. Let’s start by writing condensed formulas for the two reactants. The condensed formula for the carboxylic acid is CH3COOH. The condensed formula for the alcohol is CH3CH2OH. During the reaction, the CH3CO portion of the carboxylic acid will combine with the OCH2CH3 portion of the alcohol. The ester formed has a condensed formula of CH3COOCH2CH3. The COO portion of the molecule is the ester functional group.

Let’s pause here and take a look at the answer choices below. Choice (B) is not a correct answer choice. The molecule does not contain the ester functional group, so it is not an ester. Let’s take a look at choice (E). Choice (E) is also an incorrect choice. The molecule does not contain the ester functional group. Therefore, it is not an ester. Choices (A), (C), and (D) all have something in common. All of these molecules contain the ester functional group. Let’s draw a more complete structural formula for the ester formed in the reaction. So the ester that we’re looking for contains a total of four carbon atoms. By quickly scanning the answer choices, we see that choice (C) is an ester which contains four total carbon atoms. The correct answer is choice (C).