Question

38. What are hydro carbons? write any two differences between Alkanes and Alkenes?
Write the structural formula for the compound from aldehydes and from the ketones
having three carbon atoms.​

Answer 1

Hydro Carbons are the organic compounds made up of hydrogen and carbon only.

Alkanes , also known as paraffins , are the hydrocarbons where carbon has single bonds satisfied with hydrogen or halogens.

they are less reactive or even, least reactive, because they have all their single bonds satisfied.

Alkenes ,also known as olefins,

are the hydrocarbons formed by carbon carbon double bond, and it's subsequent bonds are satisfied by hydrogen or halogen.

they are more reactive as they have 2 bonds , which breaks to form single single bonds.

aldehydes have the general formula:

C(n)H(2n+1)CHO, where n = number of atoms.

here n= 3

thus,

C3H7CHO = propanal

general formula of ketones:

CnH2nO

thus, n= 3

=> C3H6O = propanone

Answer 2

Explanation:

hydrocarbons :-

the the compounds containing only carbon and hydrogen are called hydrocarbons these compounds are known as organic compounds

difference between alkanes and alkenes :-

I) alkanes in which the carbon atoms are linked to each other only by single bonds while in the alkenes in which carbon atoms are linked to each other by double bonds

ii) alkanes alkanes are chemically less reactive while alkene are chemically more reactive