Draw the Lewis structure for the following condensed structure

Draw the Lewis structure for the following condensed structure: CH3CCH(OH)CH3

The Correct Answer and Explanation is:

Lewis Structure of CH₃CCH(OH)CH₃:

The condensed structure CH₃CCH(OH)CH₃ corresponds to a molecule known as 3-butanol or but-2-yn-2-ol depending on the bonding. To draw its Lewis structure, we need to expand it step-by-step:

Step 1: Identify the atoms and their connectivity

The structure is written as:

CH₃–C≡C–(OH)–CH₃

This indicates:

• A CH₃ (methyl group) bonded to a carbon triple-bonded to another carbon
• That carbon is also bonded to a hydroxyl group (OH) and a second methyl group

So the skeleton is:
CH₃–C≡C–CH(OH)–CH₃

However, the formula is CH₃–C≡C–(OH)–CH₃, indicating the hydroxyl group (OH) is bonded to the same carbon that also has a methyl group. The central carbon is bonded to four things: one triple bond carbon, one OH, and one CH₃.

Step 2: Count total valence electrons

• Carbon (C) has 4 valence electrons × 4 = 16
• Hydrogen (H) has 1 valence electron × 8 = 8
• Oxygen (O) has 6 valence electrons × 1 = 6
  Total = 30 valence electrons

Step 3: Draw the structure

Here is the Lewis structure:

mathematicaCopyEdit      H   H
      |   |
H–C–C≡C–C–OH
   |       |
   H       H

Or in full bond-and-lone pair notation:

mathematicaCopyEditH   H       H   ..
|   |       |   :
H–C–C≡C–C–O
    |       |
    H       H

Note:

• The second carbon has a triple bond with the third carbon
• The third carbon forms a single bond with the OH group and another with the methyl (CH₃) group

Explanation

To draw the Lewis structure of CH₃CCH(OH)CH₃, we begin by interpreting the condensed formula. This molecule contains a carbon chain with a triple bond and a hydroxyl group (OH) attached to one of the carbons in the chain. The key to understanding this structure is recognizing the functional groups and how the atoms connect.

The CH₃ group at the start indicates a carbon with three hydrogen atoms bonded to it. This carbon connects to another carbon, which is triple-bonded to a third carbon atom. A carbon–carbon triple bond involves one sigma bond and two pi bonds, using six electrons. This third carbon is also bonded to a hydroxyl group (OH) and to another methyl group (CH₃). That central carbon forms four bonds in total, which is typical for carbon and satisfies the octet rule.

Next, we count the valence electrons. Carbon has four, hydrogen has one, and oxygen has six. In total, this gives thirty valence electrons. These electrons must be arranged so that each atom achieves a stable electron configuration. Hydrogen atoms need only two electrons, while carbon and oxygen aim for eight.

In the structure, all atoms obey the octet rule. The carbon in the triple bond shares six electrons with its neighboring carbon. The carbon attached to the OH group shares electrons with the OH, one hydrogen, one methyl group, and the triple-bonded carbon. The oxygen in OH has two lone pairs to complete its octet.

This structure is stable, complete, and reflects the proper connectivity and geometry for this organic compound.