a) Name the type of bond found in hydrocarbons
b) Hydrocarbons X and Y have melting points -190°C and -90°C respectively, which of these have minimum number of carbons in the molecule and why?
Answers
Answer:
. Hydrocarbons are organic compounds that are made of only hydrogen and carbon atoms.
2. Saturated hydrocarbons have only single bonds between carbon and hydrogen atoms and are called alkanes.
General formula: C
n
H
2n+2
Ethane:- CH
3
−CH
3
3. Unsaturated hydrocarbons have double and triple bonds between carbon atoms. They are alkenes and alkynes.
General formula: alkenes: C
n
H
2n
and alkynes: C
n
H
2n−2
Ethene (Alkene):- CH
2
=CH
2
Ethyne (Alkyne):- CH≡CH
4. Unsaturated hydrocarbons can be converted to saturated hydrocarbons by addition of hydrogen which breaks the double or triple bond.
CH
2
=CH
2
+H
2
→
Ni
CH
3
−CH
3
What are hydrocarbons? Write the name and general formula of (i) saturated hydrocarbons, (ii) unsaturated hydrocarbons and draw the structure of one hydrocarbon of each type. How can an unsaturated hydrocarbon be made saturated?
ANSWER:-
1. Hydrocarbons are organic compounds that are made of only hydrogen and carbon atoms.
2. Saturated hydrocarbons have only single bonds between carbon and hydrogen atoms and are called alkanes.
General formula: C n H 2n+2
Ethane:- CH 3 −CH3
3. Unsaturated hydrocarbons have double and triple bonds between carbon atoms. They are alkenes and alkynes.
General formula: alkenes: C n H2n and alkynes: C n H 2n−2
Ethene (Alkene):- CH 2 =CH 2
Ethyne (Alkyne):- CH≡CH
4. Unsaturated hydrocarbons can be converted to saturated hydrocarbons by addition of hydrogen which breaks the double or triple bond.
CH 2 =CH 2 +H 2→Ni CH 3 −CH3.