Question

Draw an aldehyde that has the molecular formula \(\mathrm{C}_{4} \mathrm{H}_{8} \mathrm{O}\).

Short answer

The aldehyde that has the molecular formula \(C_4H_8O\) is butanal, which can be structurally represented as \[ HC = O \] | \[ CH_2-CH_2-CH_3 \]

Step-by-step solution

Understand Aldehyde Structure

An aldehyde is characterized by the presence of a carbonyl group (C=O) where the carbon atom is also bonded to at least one hydrogen atom. This carbonyl group is typically at the end of a carbon chain. Thus, in an aldehyde with 4 carbon atoms, one carbon will be part of the carbonyl group, and the remaining 3 carbons will form a chain. Along the chain, each carbon atom is singly bonded to two hydrogens and the remaining spots are filled by the adjacent carbons.

Draw the Aldehyde

The aldehyde that matches the given molecular formula \(C_4H_8O\) is butanal. This molecule has a chain of three carbons, each bonded to two hydrogens. The remaining 2 hydrogens are bonded to the carbonyl carbon, and the oxygen atom is double bonded to the carbonyl carbon. The structure looks like this: \[ HC = O \] | \[ CH_2-CH_2-CH_3 \]

Key concepts

Carbonyl Group

Understanding the carbonyl group is fundamental when studying organic chemistry. It is a functional group composed of a carbon atom double-bonded to an oxygen atom \( =O \). This striking feature distinguishes aldehydes and ketones from other organic compounds.

The carbonyl group in aldehydes is always situated at the end of the carbon chain, making it more reactive due to its exposure. This placement affects the aldehyde's physical and chemical properties, including aspects like boiling point, polarity, and reactivity towards nucleophiles in various chemical reactions.

Importance in Chemistry

In addition to being a defining characteristic of aldehydes, the carbonyl group is also important in the formation of other essential organic compounds. It can react with alcohol to form acetals, with amines to create imines, and through reduction, it can yield alcohols. Understanding its behavior is crucial for grasping the reactivity patterns of organic molecules.

Butanal

Butanal, often referred to by its common name butyraldehyde, is an aldehyde with four carbon atoms. Its structure incorporates the aforementioned carbonyl group at the one end of a three-carbon chain, with the general formula \( \mathrm{CH_3CH_2CH_2CHO} \).

The molecule is straightforward, with the first three carbons in the chain each bonded to two hydrogen atoms, while the last carbon, which is part of the carbonyl group, is bonded to an oxygen atom with a double bond and one hydrogen atom. This structure gives butanal some distinctive properties, such as a boiling point around 75 degrees Celsius, and it's miscible with most organic solvents.

Uses in Industry

Butanal serves as an intermediate in the production of various chemicals, including resins, plasticizers, and pharmaceuticals. It is also used as a flavoring agent due to its distinctive fruity odor. Given its reactivity, it is a valuable building block in organic synthesis.

Molecular Formula

The molecular formula provides vital information about a compound, which includes the exact number of each type of atom present in a single molecule. For instance, the molecular formula \( \mathrm{C}_4\mathrm{H}_8\mathrm{O} \) represents an organic compound composed of four carbon atoms (C), eight hydrogen atoms (H), and one oxygen atom (O).

Furthermore, the molecular formula can hint at the possible structure of the molecule. Knowing that the compound in question is an aldehyde, and considering the simple molecular formula, one can deduce that it must contain a single carbonyl group attached to a saturated hydrocarbon chain.

Application in Problem Solving

Analyzing the molecular formula is a significant step in determining the structure of a compound in organic chemistry. Understanding the stoichiometric relationships allows chemists to infer possible structural formulas, characterize substances, and predict reaction outcomes, which is precisely how we identify butanal as the compound in our exercise.