Question

CH4>CH3Cl>C2H6>C2H5Cl

Answer 1

CH4->CH3Cl->C2H6->C2H5Cl

CH4+Cl2=CH3Cl+HCl

2 CH3Cl+2 Na=C2H6+2 NaCl

C2H6+Cl2=C2H5Cl+HCl

Answer 2

The order you have provided represents a decreasing order of reactivity for the substitution reaction between methane (CH4), chloromethane (CH3Cl), ethane (C2H6), and ethyl chloride (C2H5Cl).

In general, the reactivity of alkyl halides in substitution reactions can be determined by considering the stability of the carbon-halogen bond and the stability of the resulting carbocation intermediate.

The order you provided suggests that the reactivity decreases as you move from methane to ethyl chloride. Let's break it down:

1. CH4 (Methane): Methane is the least reactive among the compounds listed. This is because methane does not have any functional groups that can undergo substitution reactions.

2. CH3Cl (Chloromethane): Chloromethane is more reactive than methane because it contains a chlorine atom, which is a better leaving group than a hydrogen atom. The carbon-chlorine bond is relatively polar, making it easier to break and form a carbocation intermediate.

3. C2H6 (Ethane): Ethane is less reactive than chloromethane because it lacks a functional group that can undergo substitution reactions. Similar to methane, it does not have a leaving group.

4. C2H5Cl (Ethyl chloride): Ethyl chloride is the most reactive compound among the ones listed. It contains an ethyl group, which is more complex than a methyl group found in chloromethane. The presence of the ethyl group increases the steric hindrance, making the carbon-halogen bond less accessible for nucleophilic attack. However, it still undergoes substitution reactions due to the chlorine atom acting as a leaving group.

In summary, the reactivity order you provided is correct: CH4 < CH3Cl < C2H6 < C2H5Cl.