Question

One of the more important chemical reactions of the alkanes is?

addition
combustion
substitution
hydration

Answer 1

Combustion:

The saturated hydrocarbons are relatively inert except at high temperatures. Combustion is one of the more important chemical reactions of the alkanes.

Alkanes have the general formula of CnH2n+2. For example, an alkane with 6 carbon atoms (n = 6) would have a formula of C6H2·6+2 or C6H14. Structurally C6H14 would be shown as:

Answer 2

Answer: The correct answer is substitution reaction.

Step-by-step explanation:

Addition reaction is the chemical reaction where atoms get added to the given compound. No atom is lost during this particular reaction. In organic chemistry, only unsaturated hydrocarbons (alkenes and alkynes) shows this type of reaction.

`AB+C\rightarrow ABC`

Combustion reaction is a chemical reaction where a hydrocarbon reacts with oxygen gas to produce carbon dioxide gas and water molecule.

`\text{Hydrocarbon}+O_2\rightarrow CO_2+H_2O`

Substitution reaction is a chemical reaction where one atom replaces the other atom from the given compound. In organic chemistry, only saturated hydrocarbons (alkanes) favors this reaction.

`AB+C\rightarrow AC+B`

Hydration reaction is a chemical reaction in which hydrogen atoms get added to the compound. This reaction is favored by unsaturated hydrocarbons only (compounds which have multiple bonds).

`H_2C=CH_2+H_2\rightarrow CH_3-CH_3`

So, the reaction which is important only for alkanes is substitution reaction.