Chemistry: Organic Chemistry: Nomenclature and Isomers
Practice naming organic compounds and identifying isomers
Chemistry: Organic Chemistry: Nomenclature and Isomers
Practice naming organic compounds and identifying isomers
Chemistry - Grade 9-12
- 1
Name the compound with the condensed structural formula CH3-CH2-CH3.
The compound is propane because it has a three-carbon continuous chain and only single bonds. - 2
Name the compound with the condensed structural formula CH3-CH(CH3)-CH2-CH3.
Find the longest continuous carbon chain first, then number it to give the branch the lowest possible number.
The compound is 2-methylbutane because the longest chain has four carbons and a methyl group is attached to carbon 2. - 3
Name the alcohol with the condensed structural formula CH3-CH2-CH2-CH2-OH.
The -OH group is the alcohol functional group and must receive the lowest possible number.
The compound is butan-1-ol because it has a four-carbon chain and the hydroxyl group is attached to carbon 1. - 4
Name the alkene with the condensed structural formula CH3-CH2-CH=CH2.
The compound is but-1-ene because the four-carbon chain contains a double bond starting at carbon 1 when numbered from the nearest end. - 5
Name the compound with the condensed structural formula CH3-CH(CH3)-CH(CH3)-CH3.
Use the prefix di- when there are two identical substituents.
The compound is 2,3-dimethylbutane because the longest chain has four carbons and methyl groups are attached to carbons 2 and 3. - 6
Write a condensed structural formula for 3-ethyl-2-methylhexane.
Start with the six-carbon parent chain, then add the substituents at the numbered positions.
A correct condensed structural formula is CH3-CH(CH3)-CH(CH2CH3)-CH2-CH2-CH3. This shows a six-carbon parent chain with a methyl group on carbon 2 and an ethyl group on carbon 3. - 7
List all three structural isomers of C5H12 by IUPAC name.
The three structural isomers of C5H12 are pentane, 2-methylbutane, and 2,2-dimethylpropane. They have the same molecular formula but different carbon skeletons. - 8
Explain what structural isomers are, using C4H10 as an example.
Focus on how the atoms are connected, not just how many atoms are present.
Structural isomers are compounds with the same molecular formula but different connections between atoms. For C4H10, butane has a straight four-carbon chain, while 2-methylpropane has a branched chain. - 9
Describe the difference between cis-2-butene and trans-2-butene.
A carbon-carbon double bond does not rotate freely, so the positions of groups around it matter.
In cis-2-butene, the two CH3 groups are on the same side of the double bond. In trans-2-butene, the two CH3 groups are on opposite sides of the double bond. - 10
Name the compound CH3-CO-CH3 and identify its functional group.
The compound is propanone. Its functional group is a ketone because the carbonyl carbon is bonded to two carbon groups. - 11
Name the compound CH3-CH2-COOH and identify its functional group.
The -COOH group is named with the suffix -oic acid.
The compound is propanoic acid. Its functional group is a carboxylic acid because it contains the -COOH group. - 12
Name CH3-CH2-CH2-Br and give the name of one structural isomer with the same molecular formula.
The compound is 1-bromopropane. One structural isomer with the same molecular formula is 2-bromopropane, where the bromine atom is attached to the middle carbon. - 13
Name a benzene ring with one methyl group attached.
The IUPAC name is methylbenzene. The common name toluene is also widely used for this compound. - 14
Are 2-methylpentane and 3-methylpentane structural isomers? Explain your answer.
Compare both the molecular formula and the position of the branch.
Yes, 2-methylpentane and 3-methylpentane are structural isomers because they both have the formula C6H14, but the methyl branch is attached at a different position on the carbon chain. - 15
Explain the difference between a saturated hydrocarbon and an unsaturated hydrocarbon. Use hexane and hex-1-ene as examples.
Single bonds indicate an alkane, while a carbon-carbon double bond indicates an alkene.
A saturated hydrocarbon has only single carbon-carbon bonds, so hexane is saturated. An unsaturated hydrocarbon has at least one double or triple carbon-carbon bond, so hex-1-ene is unsaturated because it contains a carbon-carbon double bond.