Be sure to answer all parts

Be sure to answer all parts. Chloral, Cl3C-CH=O, reacts with water to form the sedative and hypnotic agent chloral hydrate, Cl3C-CH(OH)2. Draw Lewis structures for each of these substances. Draw them in decreasing molecular weight from left to right.

The Correct Answer and Explanation is:

Correct Answer:

Below are the Lewis structures, listed in decreasing molecular weight from left to right:

1. Chloral Hydrate (Cl₃C–CH(OH)₂)
2. Chloral (Cl₃C–CHO)
3. Water (H₂O)

Lewis Structures:

1. Chloral Hydrate (Cl₃C–CH(OH)₂)

mathematicaCopyEdit   Cl     Cl
    \     /
     C – C – OH
    /     \
  Cl       OH

• The first carbon (C) is bonded to three chlorine (Cl) atoms and the second carbon.
• The second carbon is bonded to the first carbon, one hydrogen, and two hydroxyl (–OH) groups.

2. Chloral (Cl₃C–CHO)

mathematicaCopyEdit   Cl     Cl
    \     /
     C – C = O
    /     \
  Cl       H

• The first carbon is bonded to three chlorine atoms and one carbon.
• The second carbon is double bonded to oxygen (C=O) and has one hydrogen.

3. Water (H₂O)

mathematicaCopyEdit   H–O–H

• Oxygen is single bonded to two hydrogen atoms and holds two lone pairs of electrons.

Explanation:

This question explores the reaction of chloral with water and requires drawing Lewis structures of the involved molecules in order of their molecular weight.

Chloral (Cl₃C–CHO) is a carbon compound with three chlorine atoms bonded to one carbon, which is also bonded to a carbonyl group (C=O) and a hydrogen. This structure is an aldehyde with electron-withdrawing chlorine atoms, making the carbonyl carbon very electrophilic and reactive toward nucleophiles like water.

Chloral Hydrate (Cl₃C–CH(OH)₂) is the product formed when chloral reacts with water. In this structure, the carbonyl group is converted into a geminal diol (two hydroxyl groups on the same carbon). This occurs when water adds across the carbonyl double bond. The electrophilic carbon in chloral is attacked by the nucleophilic oxygen of water, followed by proton transfer steps to give the hydrate.

Water (H₂O) is a small molecule with two hydrogen atoms covalently bonded to an oxygen atom. It has two lone pairs on the oxygen, which make it a good nucleophile in reactions like this.

In terms of molecular weight:

• Chloral hydrate has the highest weight due to the addition of two OH groups.
• Chloral is next with three chlorine atoms and an aldehyde group.
• Water is the lightest molecule, containing just three atoms.

This type of transformation (aldehyde to hydrate) is common in organic chemistry and underlines the principles of nucleophilic addition to carbonyl compounds.