Question

Which of the following molecules are alkanes:

• A. $C_8{H}_{16}$
• B. $C_4{H}_{9}F$
• C. $C_6{H}_{14}$
• D. $C_9{H}_{20}$

Answer 1

Answer: (C), (D)

The correct options are
C $C_6{H}_{14}$
D $C_9{H}_{20}$

Alkanes have the general formula $C_n{H}_{2n+2}$.
In $C_6{H}_{14}$ $n=6$ & $2n+2=14$. Also in $C_9{H}_{20}$ ; $n=9$ & $2n+2=20$ . Therefore $C_6{H}_{14}$ & $C_9{H}_{20}$ are alkanes.

Alkenes have the general formula $C_n{H}_{2n}$.

In $C_8{H}_{16}$ $n=8$ & $2n=16$ there its an alkene.

and $C_4{H}_{9}F$ is an alkyl halide.