Download 1. intro notes / aliphatics overview

IB CHEMISTRY
TOPIC 10/20: ORGANIC CHEMISTRY
BRIEF HISTORY OF ORGANIC CHEMISTRY
*The term organic literally means “derived from _________________ organisms”.
*Originally, organic chemistry involved the study of compounds extracted from living organisms. It was believed that organic
compounds needed a “vital force” to create them.
*However, in 1828 Friedrich Wohler synthesized _______________ (organic) from ________________ chemicals. (Some chemists
claimed that a trace of the vital force from Wohler’s hands must have contaminated the reaction.) This discovery profoundly changed
the world of chemistry – 400,000 organic compounds were synthesized over the next 60 years!
*The modern definition of organic chemistry is the chemistry of _____________ compounds – the compounds it makes and the
reactions it undergoes. All organic compounds contain carbon. However, not all carbon containing compounds are considered
organic. (e.g. CO2, SiC, CaCO3, HCN, NH4SCN, diamond, graphite) **Most of the millions of carbon compounds are considered to
be organic, however. Carbon forms more compounds than are known of all the other elements in the Periodic Table put together!
*HYDROCARBONS - Nearly all organic compounds are structured from a “backbone” that consists of _______________ and
______________.
*Other elements common in organic chemistry include:
*Origins of Hydrocarbons and Other Organic Compounds = _________________Fuels
ORIGIN OF FOSSIL FUELS
1. Coal  remains of land-based plants
2. Petroleum(crude oil)  remains of marine-based plants, plant-like organisms and animal-like organisms
3. Natural gas  same as petroleum
WHAT MAKES CARBON UNIQUE?
FEATURE
1. # OF VALENCE
ELECTRONS
DESCRIPTION
Carbon has ____bonding electrons; that is, it has a valence of ____. It ALWAYS
forms ____ covalent bonds.
2. MULTIPLE BONDING
Carbon can form multiple bonds - ___________, __________ and ____________
bonds with itself and with atoms of other elements such as ____________ and
____________.
3. CONCATENATION
Carbon has the unique ability to concatenate; that is, to form __________ and
__________. In some polymers there can be well over ________ carbon atoms in
a single chain.
4. CANNOT EXPAND OCTET
Carbon cannot expand its __________of valence electrons. This makes carbon
compounds very stable. (The element below carbon, ______________, is able to
expand its octet. This decreases the stability of silicon compounds.)
5. BOND STRENGTH
The C-C bond and the C-H bond is relatively strong. This, again, increases the
stability of carbon compounds.
 It is the diversity of carbon compounds that provides the basis for life on Earth. Living creatures are largely composed of complex
organic compounds that serve ___________________, _______________, or ______________ functions.
 Synthetic organic products serve as drugs, medicines, plastics, pesticides, paints and fibers.
 Many of the most important advances in medicine are actually advances in organic chemistry.
ALIPHATICS: OVERVIEW
Bonding
ALKANES
- All single (covalent)
ALKENES
- at least one ____________
bond
ALKYNES
- at least one ____________
bond
“
“
Structural diagram
of 2-carbon example
N/A
Name & structure of
functional group
Saturated or
unsaturated?
Shape around
Carbon
Bond Angle
Hybridization
Name of 2-Carbon
example
Nomenclature
“
” ending
” ending
” ending
General Formula
*If a hydrocarbon is saturated, other atoms ______________ be added to the compound; however, atoms in a saturated
hydrocarbon may be ____________________ (i.e. replaced) with other atoms.
- What is probably the easiest way of determining whether compound is saturated or not?
- What is the difference between a saturated and unsaturated fat? What major implication does the type of saturation have
on the properties of a fat?...with respect to potential adverse health effects.
**Construct models of ethane, ethene and ethyne and examine how the shape and bond angles are altered by the
inclusion of a double/triple bond.
IMPORTANT DEFINITIONS
(i) HOMOLOGOUS SERIES – a series of compounds within the same family/class; with the same general formula;
which has successive members that differ from each other by a common structural unit – usually a ‘CH2’ group.
*Members of the same homologous series have similar ________________ properties and show a _____________
change in physical properties (e.g. boiling point and size of an alkane are positively correlated).
Examples of different homologous series:
HOMOLOGOUS SERIES
GENERAL FORMULA
ALKANES
ALKENES
ALKYNES
ALCOHOLS
ALDEHYDES
KETONES
CARBOXYLIC ACIDS
(ii) ORGANIC FAMILY  a group of organic compounds with common structural features (e.g. the same functional
group) that impart characteristic/similar physical and chemical properties (Examples include: alkanes, alkenes, alkynes,
halogenoalkanes, alcohols, ethers, aldehydes, ketones, esters, carboxylic acids, amines, amides, nitriles and arenes)
(iii) FUNCTIONAL GROUP  the _______________ parts of molecules; the attribute of the molecule that defines its
classification; a structural arrangement of atoms that imparts particular characteristics to the molecule (e.g. phenyl,
hydroxyl, carbonyl, carboxyl, carboxyamide, aldehyde, ester, ether, amine, nitrile, alkyl, alkenyl, alkynyl)
- Each organic family contains a different functional group (e.g. aldehydes contain the _____________ functional group).
FORMULAS & STRUCTURES  REPRESENTING ORGANIC COMPOUNDS
TYPE OF FORMULA
EMPIRICAL Formula
DESCRIPTION
- provides simplest/lowest ____________ of elements
MOLECULAR/ACTUAL
Formula
- provides _____________ number of each type of atom in
molecule
- does not give __________________.
- could be isomers so name cannot be generated from a
molecular formula only
- explicitly shows each bond
COMPLETE
STRUCTURAL
FORMULA
CONDENSED
STRUCTURAL
FORMULA
LINE STRUCTURAL
FORMULA
- Usually written on one line in the order that atoms are
attached to give structural information w/o taking up space
by drawing bonds.
- Does not give information about stereoisomers.
- Gives the general shape of the molecule.
- Condensed b/c hydrogen atoms are left off and
___________ represent carbon atoms.
- No lone pairs are shown.
- Can be used to generate a name for the compound but
doesn’t show stereoisomers unless used with Dash-wedge
formula.
- If O, N, or S are part of a structure, they must be shown.
DASH-WEDGE /
(STEREOCHEMICAL)
STRUCTURAL
FORMULA
- A representation of the 3-D structure.
- These formulas allow you to identify stereoisomers.
(a) The lines show bonds in the plane of the page
(b) The dark triangle represents a bond coming out of the
page
(c) The dashed line represents a bond going out of the back
of the page
LEWIS Structures
- Shows the location of all the electrons, including lone
pairs. Identifies isomer so that name can be generated.
*ACTIVITY: Draw complete structures for each:
(i) (CH3)2CHCH2CH(OH)CH3
(ii) CH3COOH
(iii) CH3CHO
EXAMPLE(S)
C2H5 (…is the empirical formula of
butane, C4H10)
C4H10 (…is the molecular/actual
formula of butane and
methylpropane)
CH3CH2CH2CH3
OH