2 - methyl propan -2- ol is an example of a

1. Analyze the question

The question asks us to classify 2-methylpropan-2-ol based on its structure as an alkanol (alcohol).

2. Explain the concept

Alkanols are classified as primary, secondary, or tertiary based on the number of alkyl groups attached to the carbon atom that carries the hydroxyl (-OH) group:

• Primary ($1^\circ$) alkanol: The carbon atom bonded to the -OH group is attached to only one other carbon atom (or no other carbon atoms, as in methanol).
• Secondary ($2^\circ$) alkanol: The carbon atom bonded to the -OH group is attached to two other carbon atoms.
• Tertiary ($3^\circ$) alkanol: The carbon atom bonded to the -OH group is attached to three other carbon atoms.

3. Show the solution

Let’s draw the structure of 2-methylpropan-2-ol:

1. Parent chain: "Propan" means 3 carbons in the main chain.
2. Position of -OH: "2-ol" means the -OH group is on the second carbon.
3. Substituent: "2-methyl" means a methyl group ($-CH_3$) is also on the second carbon.

The structure looks like this:

        CH3
        |
  CH3 - C - CH3
        |
        OH

• Identify the carbon atom bonded to the -OH group (the central carbon).
• Count how many other carbon atoms are directly attached to this central carbon.
• We can see there are three methyl groups ($-CH_3$) attached to that central carbon.

Since the carbon bearing the -OH group is attached to three other carbon atoms, it is a tertiary alkanol.

4. Identify the answer

Comparing our finding to the options provided: A. Primary alkanol B. Secondary alkanol C. Tertiary alkanol D. Quaternary alkanol (Note: This is not a standard classification for alcohols).

The correct option is C.

5. Tip

Memory Trick: Think of the number of carbons attached to the "functional carbon."

• 1 carbon attached = Primary (1st)
• 2 carbons attached = Secondary (2nd)
• 3 carbons attached = Tertiary (3rd)