How can I identify a double chain hydrocarbon​

Explanation:

Unsaturated hydrocarbons have one or more double or triple bonds between carbon atoms. Those with double bond are called alkenes and those with one double bond have the formula CnH2n (assuming non-cyclic structures). ... Alkanes have the general formula CnH2n+2.

If more than one double bond is present, indicate their position by using the number of the first carbon of each double bond and use the suffix -diene (for 2 double bonds), -triene (for 3 double bonds), -tetraene (for 4 double bonds), etc.

Explanation:

colorless gas, exhibiting a blue glow when placed in an electric field

b) solid

its a type of rock