Question

What is an alkyl group? How is a given alkyl group related to its parent alkane?

Short answer

An alkyl group is a fragment of an alkane molecule with one hydrogen atom removed, denoted by the symbol 'R,' and is named by replacing the 'ane' suffix of the parent alkane with 'yl.' For example, methyl (CH3) is an alkyl group derived from methane (CH4). The relationship between an alkyl group and its parent alkane lies in the formation of the alkyl group, which involves removing one hydrogen atom from the alkane and creating a reactive site on the carbon atom. This allows the alkyl group to bond with other atoms or functional groups in organic molecules.

Step-by-step solution

Definition of an Alkyl Group

An alkyl group is a fragment of an alkane (hydrocarbon) molecule that has one hydrogen atom removed. These groups are denoted by the symbol 'R' and are generally found attached to other atoms or functional groups in organic molecules. Alkyl groups are named by replacing the 'ane' suffix of the parent alkane with the 'yl' suffix. For example, methyl is an alkyl group derived from methane.

Relationship between an Alkyl Group and its Parent Alkane

To understand the relationship between an alkyl group and its parent alkane, let's consider how an alkyl group is formed: 1. Take the parent alkane: The alkane is a hydrocarbon molecule containing only single covalent bonds between its carbon atoms (C) and hydrogen atoms (H). The general formula for an alkane is CnH2n+2, where n is the number of carbon atoms. 2. Remove one hydrogen atom: To form an alkyl group, remove one hydrogen atom (H) from the alkane molecule. This removal will generate a reactive site on the carbon atom that is lacking a hydrogen atom, and it can now bond with other atoms or groups. 3. Naming the alkyl group: Replace the 'ane' suffix of the parent alkane's name with 'yl.' For example, if we remove one hydrogen atom from methane (CH4), the alkyl group formed is called methyl (CH3). Similarly, the alkyl group derived from ethane (C2H6) would be ethyl (C2H5). In summary, an alkyl group is a fragment of its parent alkane with one hydrogen atom removed, and it is named by replacing the 'ane' suffix of the alkane with 'yl.' These alkyl groups can combine with other atoms or groups to form various organic compounds.