Question

How would you explain an ethyl group?

Answer 1

Its an alkyl derivative of ethane.

Explanation:

Alkanes have the formula `C_n H_(2n+2)` where in n is the number of carbon atoms.

Alkanes have their carbons saturated with hydrogens and have no double bonds. An example is ethane.

`CH_3CH_3` or simply `C_2H_5`

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Now let us have a look in alkyl groups.

Alkyl groups are organic groups(they usually act as substituents) that are alkanes lacking one carbon and hence, `C_2H_(2n+1)` . Because they are derived from alkanes, we call them alkane derivatives.

Take a look at the structure given above. Remove 1 hydrogen from `C_2H_6` (which is an alkane, `C_((2))H_(2(2)+2) = C_2H_6`, proving it is an alkane), the resulting structure is `C_2H_5`, an alkyl group.

Remember that carbons have to be tetravalent. That is, its valence electrons need 4 electrons to bond covalently (see Octet rule). However, because we removed 1 Hydrogen atom, there is one valence electron that has no partner.

So some atoms or groups may bind to that missing valence electron. For example, i chose to put a hydroxyl group (OH-) to satisfy the missing valence electron. The resultant compound is now `C_2H_5OH`, ethyl alcohol.

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