Question

CH4>CH3Cl>C2H6>C2H5Cl | | ^ ^C2H2 C2H4

Answer 1

1)CH4+Cl2=CH3Cl+HCl

2)2 CH3Cl+2 Na=C2H6+2 NaCl

3) C2H6+Cl2=C2H5Cl+HCl

4)2 CH4=C2H2+3 H2↑

5)C2H2+H2↑=C2H4

Answer 2

The given sequence represents the order of reactivity of the mentioned compounds in a free-radical halogenation reaction:

CH4 > CH3Cl > C2H6 > C2H5Cl

This sequence shows that methane (CH4) is the least reactive towards free-radical halogenation, while chloromethane (CH3Cl) is more reactive. Additionally, ethane (C2H6) is less reactive than chloroethane (C2H5Cl).

The halogenation of alkanes typically involves the substitution of a hydrogen atom with a halogen (e.g., chlorine or bromine) atom in the presence of UV light or heat, generating free radicals. The reactivity of these alkanes is determined by the stability of the intermediate free radicals formed during the reaction.

To further illustrate the reactivity order, we have two other compounds connected by a double-headed arrow (| |):

C2H2 (acetylene) and C2H4 (ethylene)

This represents a comparison between acetylene (C2H2) and ethylene (C2H4) regarding their reactivity in a different type of reaction: an addition reaction.

Acetylene (C2H2) is more reactive than ethylene (C2H4) in an addition reaction because acetylene's triple bond is more easily broken compared to the double bond in ethylene.

In summary, the given sequence represents the relative reactivity of the compounds towards free-radical halogenation (for the first four compounds) and an addition reaction (for the last two compounds).