Question

Find the alkyne among all the other alkanes in the given options.

• A. $C_3{H}_8$
• B. $C_4{H}_6$
• C. $C_5{H}_{12}$
• D. $C{H}_4$

Answer 1

The correct option is B

$C_4{H}_6$

An alkyne is a hydrocarbon in which at least two carbon atoms are joint to each other by a triple bond.

The general formula for alkyne is $C_n{H}_{2n-2}$. So if you put the value of $n$ equal to the number of carbon atoms in the given options we will know which option is the correct one.

For $n=1$
$C_1{H}_{2\times 1-2}$ = $C_1{H}_0$ This compound is not possible as this is only a carbon atom.

For $n=3$,
$C_3{H}_{2\times 3-2}$ = $C_3{H}_4$ This is not equal to $C_3{H}_8$

For $n=4$,
$C_4{H}_{2\times 4-2}$ = $C_4{H}_6$ This is equal to $C_4{H}_6$

For $n=5$
$C_5{H}_{2\times 5-2}$ = $C_5{H}_8$ This is not equal to $C_5{H}_{12}$

So amond the given options $C_4{H}_6$ is the only alkyne among the given options.