Chapter 11: Nomenclature
No description yet. This curated deck is ready for daily study.
Card preview (24)
What groups can hydrocarbons be classified into?
• Aliphatic • Alicyclic • Aromatic
What is an aliphatic compound?
• A compound containing carbon and hydrogen joined together in straight chains, branched chains or non-aromatic rings
What is an alicyclic compound?
• An aliphatic compound arranged in non-aromatic rings with or without side chains
What is an aromatic compound?
• A compound containing a benzene ring
What are alkanes?
• Hydrocarbons containing single carbon-carbon bonds
What are alkenes?
• Hydrocarbons that contain at least one carbon-carbon double bond
What are alkynes?
• Hydrocarbons that contain at least one carbon-carbon triple bond
What is an alkyl group?
• A side chain formed by removing a hydrogen atom from an alkane parent chain • It has the formula CnH2n+1 • It is often shown as R
What is an aryl group?
• A group containing a benzene ring
What does the stem of a molecule’s name show?
• The number of carbon atoms in the largest continuous chain
What do prefixes show about a molecule?
• The presence of side chains or functional groups
What does the suffix of a molecule show?
• Functional groups
List the 5 main rules for nomenclature.
• Identify the suffix • Identify the longest continuous chain • Number the carbons • Identify which number carbon the side chains and functional groups are on • Combine the suffix, stem and side chains to name the compound
What do you do if there are 2 continuous chains of the same length?
• The one with more branches is the longest
Which end do you number the carbons from?
• The side that will give side chains/ functional groups the lowest number • If the numbers would be the same either way, you give higher priority functional groups the lowest numbers
List the 8 main functional groups in order of decreasing priority.
• Carboxylic acids • Aldehydes • Ketones • Alcohols • Alkenes • Benzene • Halogens • Alkanes
How do you indicate that there are multiple of the same side chain/ functional group?
• You use the prefixes di, tri and tetra
How do you bring the prefixes, suffixes and stems of molecules together?
• You write the side chains/ other functional groups in front of the stem in alphabetic order (ignoring prefixes such as di, tri and tetra) • You put commas between numbers and dashes between numbers and letters • If there are 2 suffixes that need to go after the stem, the lower priority one becomes a prefix instead Since the stem is mostly the alkane’s name: • If the stem is followed by a vowel, it loses its e (propanol) • If it is followed by a consonant, it keeps the e (ethanenitrile)
How are alicyclic alkanes named?
• In the same way as alkanes, but the prefix ‘cyclo’ is added • When a cycloalkane is the shorter chain, it is named like an alkyl group, and the prefix ‘cyclo’ is still used
How are haloalkanes named?
• The following prefixes are added: • chloro • bromo • iodo
How are alkenes named?
• In the same way way as alkanes, but with the suffix ‘ene’ • If the longest chain has 4 or more carbons, the position of the double bond has to be shown • Di, tri or tetra are used if there are multiple double bonds • E.g. but-2-ene/ penta-1,3-diene
How are alcohols named?
• With the suffix ‘ol’, and a number before it to show where the hydroxyl group is • However, if a higher priority functional group is present, it is shown using the prefix ‘hydroxy’ instead
What is a ketone?
• Carbon-oxygen double bond (in the middle of a chain), which is known as a carbonyl group
How are ketones named?
• With the suffix ‘one’, and the number before it • If necessary, with the prefix ‘oxo’