What is an alkane substitution reaction? Give the names and possibilities of different types of substitution reactions.

(N/A) In alkanes,one or more hydrogen atoms can be substituted with a halogen,nitro group,or sulphonic acid group. These reactions are known as substitution reactions.
$(a)$ Nitration: The hydrogen atom of an alkane is substituted with a $-NO_{2}$ group.
$(b)$ Sulphonation: The hydrogen atom of an alkane is substituted with a $-SO_{3}H$ group.
$(c)$ Halogenation: The hydrogen atom of an alkane is replaced with a halogen ($F$,$Cl$,$Br$,$I$). The reactivity order of halogens is: $F_{2} > Cl_{2} > Br_{2} > I_{2}$.
$(d)$ Fluorination: This reaction is highly exothermic and violent,making it difficult to control. Example: $CH_{4} + F_{2} \xrightarrow{N_{2} \text{ or } Ar} CH_{3}F + HF$.
$(e)$ Iodination: This reaction is very slow and reversible. It can be driven to completion in the presence of oxidizing agents like $HIO_{3}$ or $HNO_{3}$.
$CH_{4} + I_{2} \rightleftharpoons CH_{3}I + HI$
$HIO_{3} + 5HI \rightarrow 3I_{2} + 3H_{2}O$
$(f)$ Chlorination and Bromination: These are controlled reactions. If chlorine is present in excess,all hydrogen atoms are substituted with $-Cl$ atoms.
$CH_{4}$ $\xrightarrow{h\nu, Cl_{2}, -HCl} CH_{3}Cl$ $\xrightarrow{h\nu, Cl_{2}, -HCl} CH_{2}Cl_{2}$ $\xrightarrow{h\nu, Cl_{2}, -HCl} CHCl_{3}$ $\xrightarrow{h\nu, Cl_{2}, -HCl} CCl_{4}$
Example: $CH_{3}-CH_{3} + Cl_{2} \xrightarrow{h\nu} CH_{3}-CH_{2}Cl + HCl$ (Ethane $\rightarrow$ Chloroethane).
These reactions occur at temperatures between $573 \ K$ and $773 \ K$ or in the presence of diffused sunlight or $UV$ light.