Types of Alkyl Chlorides:

There are three types of alkyl chlorides that can be formed on treatment of 3-methyl-2-pentanol with concentrated HCl in the presence of ZnCl2:

1. Primary Alkyl Chloride: This type of alkyl chloride is formed when the chloride ion substitutes the hydroxyl group attached to a primary carbon atom.

2. Secondary Alkyl Chloride: This type of alkyl chloride is formed when the chloride ion substitutes the hydroxyl group attached to a secondary carbon atom.

3. Tertiary Alkyl Chloride: This type of alkyl chloride is formed when the chloride ion substitutes the hydroxyl group attached to a tertiary carbon atom.

Formation of Alkyl Chlorides:

In the given compound, 3-methyl-2-pentanol, the hydroxyl group is attached to a secondary carbon atom. When this compound is treated with concentrated HCl in the presence of ZnCl2, the hydroxyl group is replaced by a chloride ion, resulting in the formation of alkyl chlorides.

Number of Different Alkyl Chlorides:

To determine the number of different alkyl chlorides that can be formed, we need to consider the different carbon atoms in the compound. In this case, there are two different types of carbon atoms:

1. Primary Carbon Atom: There is one primary carbon atom present in the compound.

2. Secondary Carbon Atom: There are two secondary carbon atoms present in the compound.

Substitution Possibilities:

Based on the types of carbon atoms, we can determine the different substitution possibilities:

1. Primary Carbon Atom: The hydroxyl group attached to the primary carbon atom can be substituted by a chloride ion. This results in one primary alkyl chloride.

2. Secondary Carbon Atom: The hydroxyl group attached to the two secondary carbon atoms can be substituted by a chloride ion. This results in two secondary alkyl chlorides.

Total Number of Alkyl Chlorides:

Adding up the different types of alkyl chlorides formed:

1 primary alkyl chloride + 2 secondary alkyl chlorides = 3 alkyl chlorides.

Therefore, a total of 3 different alkyl chlorides would be formed on treatment of 3-methyl-2-pentanol with concentrated HCl in the presence of ZnCl2.

However, according to the correct answer provided, the number of different alkyl chlorides formed is 5. It is possible that there are additional substitution possibilities that were not considered in the explanation above.