Functional Groups and Isomerism

Functional Groups and Isomerism

• This module helps to master functional groups and isomerism
• The language used recognizes the diverse vocabulary level of students
• The lessons are standard and follow a sequence that might need to change depending on textbook

Learning Competencies

• Describe different functional groups (STEM_GC11OCIIg-j-87)
• Describe structural isomerism and give examples (STEM_GC11OCIIg-j-89)

Module Lesson Topics

• Lesson 1: Functional Groups
• Lesson 2: Isomerism

The module enables the participant to:

• Define organic chemistry
• Define functional group
• Enumerate and explain different functional groups
• Cite uses of compounds bearing different functional groups
• Define structural isomerism
• Give examples of structural isomerism

Organic Chemistry

• Organic chemistry studies carbon-containing compounds, including hydrocarbons and compounds with other elements like oxygen, nitrogen, and halogens
• Animals, plants, and other life forms consist of organic compounds
• Organic compounds are distinguished according to their functional group

Covalent Bonds

• Covalent bonds are formed by sharing electrons in the valence shell, usually between two non-metals
• Examples of covalent bonds include water (H2O), carbon monoxide (CO), carbon tetrachloride (CCl4), methane (CH4), and acetylene (C2H2)
• Some covalent compounds can also be organic compounds

Organic Compounds

• Organic compounds are important in industry and daily life
• They are used as fuel, in plastics, synthetic fibers, perfume, and food additives
• Organic compounds can be classified as functional groups

Functional Group

• Functional group is a group of atoms or organization of bonds that determine specific properties of molecules
• Functional groups play an important role in organic compounds
• The same functional group has similar behavior and properties

Hydrocarbons

• Hydrocarbons are organic compounds containing only hydrogen and carbon
• They can be classified as aliphatic or aromatic

Aliphatic Hydrocarbons

• Aliphatic hydrocarbons are straight-chained, branched, or cyclic compounds, without a benzene ring
• Naming aliphatic hydrocarbons involves using prefixes based on the number of carbon atoms and adding a suffix based on the functional group
• Prefixes for carbon numbers 1-10: meth, eth, prop, but, pent, hex, hept, oct, non, dec

Alkane

• Saturated hydrocarbon with only single bonds
• Formula: CnH2n+2
• When C = 1, Chemical Formula: CH4 (methane)

Alkyl

• Alkane with one less hydrogen
• Formula: CnH2n+1
• When C = 1, Chemical Formula = CH3 (methyl)

Cycloalkanes

• Monocyclic saturated hydrocarbon with carbon atoms joined in rings
• Fewer hydrogen atoms than alkanes
• Formula: CnH2n
• When C = 3, Chemical Formula: C3H6 (cyclopropane)

Alkene

• Unsaturated hydrocarbon with a double bond between two carbon atoms
• Formula: CnH2n
• When C = 3, Chemical Formula: C3H6 (propene)

Alkyne

• Unsaturated hydrocarbon with a triple bond between two carbon atoms
• Formula: CnH2n-2
• When C = 2, Chemical Formula: C2H2 (ethyne or acetylene)

Aromatic Hydrocarbons

• Unsaturated hydrocarbon ring structure with fragrant properties

Arenes

• Aromatic hydrocarbon with at least one aromatic ring
• Arenes have alternating double and single bonds between carbon atoms forming rings
• Formula: R-
• Chemical Formula: C6H6 (benzene)
• Chemical Formula: C6H5CH3 or C7H8 (methylbenzene or toluene)

Hydrocarbon Derivatives

• Hydrocarbon derivatives are organic compounds made of carbon and hydrogen atoms with specific groups of atoms attached
• Containing Halogen:
  • Alkyl Halides
    • Also known as haloalkanes, these are compounds in which one or more hydrogen atoms in an alkane have been replaced by halogens
    • Formula: R – X
    • R - alkyl group, X – halogen
    • Chemical Formula: CH3CH2Cl (ethylchloride or chloroethane)
  • Aryl Halides
    • Also known as haloarenes, have a halogen directly bonded to a carbon of an aromatic ring
    • Formula: C6H5 - X
    • C6H5 – phenyl, X - halogen
    • Chemical Formula: C6H5 – Br (bromobenzene or phenyl bromide)

Containing Oxygen:

• Alcohol
• Alcohol is an organic compound with a hydroxyl (OH) functional group on an aliphatic carbon atom.
• Formula: R – OH
• Chemical Formula: CH3OH (methyl alcohol)
• Phenols
  • An organic compound with a hydroxyl (OH) attached directly to an aromatic ring
  • Formula: Ar – OH
  • Chemical Formula: C6H5BrO or (2-bromophenol)
• Ethers
  • Organic compounds containing an oxygen atom connected to two aryl or alkyl groups
  • Formula: R – O – R’
• Chemical Formula: CH3CH2–O–CH2CH3 (diethyl ether)
• Aldehydes
  • Organic compounds with at least one attached group that must be a hydrogen atom
  • Formula: RCHO
  • Chemical Formula: CH3CHO or C2H4O (acetaldehyde)

Ketones

• Ketone are an organic compound with two carbon groups are attached to the carbonyl carbon atom
• Formula: RCOR’
• R -alkyl group ; Ar – aryl group
• Chemical Formula: CH3COCH3 or C3H6O (propanone or acetone)

Carboxylic Acids

• Carboxylic Acids are an organic compound in which the carbon atom of the carboxyl group may be attached to a hydrogen atom and to a carbon chain
• Formula: R – COOH
• Chemical Formula: C3H7COOH or C4H8O2 (butanoic acid)
• Ester - organic compound with pleasant odor, derived from substitution of carboxylic acid and an alcohol
  • Formula: RCOOR
  • Chemical Formula: HCOOC3H7 or C4H8O2 (propyl methanoate)

Containing Nitrogen:

• Amines
  • Organic compounds containing nitrogen, and carbon-nitrogen bonds
  • Formula: R – NH2
  • Chemical Formula: CH3 – NH2 (methylamine)
• Amides
  • Organic compounds also known as carboxamides, characterized by a carbonyl group linked to a nitrogen atom
  • Formula: R - CO - NH2
  • Chemical Formula: CH3CONH2 (acetamide)

Isomerism

• Isomerism is a condition where two or more compounds have the same chemical formula but different structural formula
• Isomers came from “iso” meaning same and “meros” meaning parts are the compounds exhibiting this condition
• There are two types of isomerism, the structural isomerism and stereoisomerism

Types of Isomers

• Structural Isomer:
• Also known as constitutional isomers, have the same molecular formula but different structures.
• Chain Isomers
• Also known as skeletal isomers, these isomers have the same molecular formula but differ in branching of carbon atoms in straight or branched chain.
• Example: C4H10 (butane)
• Position Isomers
• Isomers having same molecular formula but differ in the position of the substituent atoms
• Example: C3H7Br
• Functional Isomers
• Isomers that have the same molecular formula but differ in functional group present.
• Example: 1. C3H6O
• Metamerism
• An isomer in which the size of a carbon chain on each side of a functional group are different.
• Example: 1. C4H10O
• Ring-Chain Isomers
• An isomer in which one isomer is an open-chain and the other has a ring structure.
• Example: C3H6

Stereoisomers:

• Also known as spatial isomers, they are the compounds with the same molecular formula and structure but different in orientation and arrangement of atoms in space

Geometric Isomers

• Also known as configurational isomers, they have the same molecular formula but different spatial arrangements of atoms
• “cis” - from Latin word meaning “the side of”, it means the functional group are on the same side of the carbon chain
• "trans" – from Latin word meaning “the other side of”, it means the functional group are on the other side of the carbon chain
• optical isomers - or enantiomers having same molecular formula but different spatial arrangements of atoms, but which have non-superimposable mirror image