Question

CHEMISTRY HELP PLEASE!
1) Name the following compound: (Pictures below are in order with the questions)
2-ethylpentane
4-ethylpentane
3-methylpentane
3-methylhexane

2) Name the following compound:
2-methyl-3-butane
2-methyl-2-butene
3-methyl-2-butene
2-methyl-2-butyne

3) Name the following compound:
4-ethyl-6-dodyne
3-propyl-5-nonyne
7-ethyl-4-dodyne
7-propyl-4-nonyne

4) Name the following compound:
2-methyl-3-ethylbutane
2-methyl-3-methylpentane
2,3-dimethylpentane
2,3-methylpentane

5) Name the following compound:
CH3 – CH2 – CH2 – CH2 – OH
1-butane
1-butanol
4-butanol
butanol

6) Name the following compound:
CH3 – CH2 – CH2 – O – CH2 – CH2 – CH2 – CH3
butyl propyl ether
propyl butyl ether
3-butyl propyl ether
4-propyl butyl ether

Answer 1

1) is called 3-methyl hexane because we choose the longest possible continuous chain which has 6 carbons and start numbering from the side that gives the branch lowest possible number.

2) is called 2-methyl-2-butene because we have to give the double bond lowest possible number but in this case double bond in position 2 from both sides so we start from the side gives the branch number 2 not 3

3)  is called 7-Ethyl-4-decyne because we have to start from the side that gives the triple bond lowest possible number which is 4 and the branch will be at position 7 (note that the name of 10 carbon is incorrectly written in the choices is called decane (as alkane) or decyne when contains triple bond)

4) is called 2,3-Dimethyl pentane because it is 5 carbons (pentane) and we have two branches of the same alkyl (dimethyl) in positions 2 and 3

5) is called 1-Butanol because it contains 4 carbons and has one OH as functional group which take the suffix -ol in position 1 so we said the name as 1-butanol (remember to give the functional group lowest possible number)

6) is called propyl butyl ether because the longest chain is 4 carbons which called butyl and the smallest chain is propyl, it also has another name 1-Propoxy butane 

Answer 2

Answer :

(1) The correct option is, 2-ethylpentane

(2) The correct option is, 2-methyl-2-butene

(3) The correct option is, 7-ethyl-4-dodyne

(4) The correct option is, 2,3-dimethylpentane

(5) The correct option is, 1-butanol

(6) The correct option is, propyl butyl ether

Explanation :

The basic rules for the naming of organic compounds are :

• First choose the longest possible carbon chain.
• The longest possible carbon chain should include the carbons of double or triple bonds.
• The naming of alkane is done by adding the suffix -ane, alkene by adding the suffix -ene, alkyne by adding the suffix -yne and carboxylic acid by adding the suffix -oic acid.
• The numbering is done in such a way that first carbon of double or triple bond gets the lowest number.
• The carbon atoms of the double or triple bond get the preference over the other substituents present in the parent chain.
• If two or more similar alkyl groups are present in a compound, the words di-, tri-, tetra- and so on are used to specify the number of times of the alkyl groups in the chain.