How many five-carbon groups are possible?

Options

A. (1) Eight
B. (2) Seven
C. (3) Six
D. (4) Five

Answer

A

Explanation

An alkyl group is the structure remaining after one `H` is removed from an alkane. Corresponding to the molecular formulas `C_(5)H_(12)`, three alkanes are possible: `n`-pentane, isopentane, and neopentane. `n`-pentane has three different types of `H` atoms, thus three different alkyl groups can be derived from it:

Isopentane has four different types of `H` atoms, thus four different alkyl groups can be derived from it:

Neopentane has just one type of `H` atoms, thus, only one alkyl group can be derived from it.