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Gr. 12 Organic Chemistry Cheat Sheet by

Introd­uction

The term organic generally means "­som­ething made from the earth" or "not chemically synthe­siz­ed."­
Organic chemistry refers to the study of compounds that contain carbon atoms as the principal element.
The simplest organic compounds are hydroc­arbons made from C and H atoms
Despite the term organic generally meaning "­nat­ura­l," organic compounds can in fact be chemically synthe­sized (first synthe­sized organic compound was urea - found in mammal urine)
Carbon has a bonding capacity of 4 so each C atom must always make 4 bonds within a compound

General Nomenc­lature

Usual follows order prefix + root + suffix
Prefix
Indicates name/m­ult­iplying prefix­es/­pos­ition of branches
Root
Indicates number of carbons in the parent chain
Suffix
Indicates the parent chain's functional group

Root Name/B­ranch Prefixes

Number of C atoms / branches
Root prefix
Multip­lying prefix
1
meth-
mono-
2
eth-
di-
3
prop-
tri-
4
but-
tetra-
5
pent-
penta-
6
hex-
hexa-
7
hep-
hepta-
8
oct-
octa-
9
non-
nona-
10
dec-
deca-
Special nomenc­lature prefixes: See Importance of Functional Groups, Haloal­kyl­/Other Functional Groups, and Special Alkyl Branches

All prefixes are listed in alpha order when writing the name of an organic compound, except for cyclo- and iso-.

Importance of Functional Groups

Functional Group
Suffix if Highest Precedence
Prefix if Lower Precedence
RC(=O)OH (carbo­xylic acid)
-oic acid 2
carboxy-
RC(=O)OR' (ester)
[branch]1-yl [root]1-oate
alkoxy­car­bonyl-
-amide
carbamoyl-
RC≡N (nitrile)
-nitrile
cyano-
RC=O (aldehyde)
-al 3
oxo-3
RC(=O)R' (ketone)
-one
oxo-
R(OH)R' (alcohol)
-ol
hydroxy-
-amine
amino-
RC=CR' (alkene)
-ene 4
Always used as a suffix
RC≡CR' (alkyne)
-yne 4
Always used as a suffix
RCCR' (alkane)
-ane
Always used as a suffix
R(X)R'
Always used as a prefix
See Haloal­kyl­s/Other Functional Groups
[1][branch] and [root] refer to the length of the carbon group's prefix (meth-, eth-, prop-, etc.)
[2]If the carbon in the RCOOH group is not the parent chain, the highest precedence suffix is -carboxylic acid
[3]If the carbon in the RCO group is not the parent chain, the highest precedence suffix is -carbal­dehyde, and the alternate prefix is formyl-
[4]If a compound is both an alkene and an alkyne, both -ene and -yne are used

Haloal­kyl­s/Other Functional Groups

Functional Group
Prefix
R-O-R' (ether)1
[branch]-oxy-
R-C-R (cyclo­alkyls)
cyclo-
fluoro-
bromo-
chloro-
iodo-
nitro-
ortho-[bran­ch(es)]
meta-[bran­ch(es)]
para-[bran­ch(es)]
[1]Ethers take precedence in prefixes over all other prefixes, except the branches attached to the ether group
[2]Applies only to benzene ring branches

Special Alkyl Branches

Propyl
Butyl
n-propyl (normal)
n-butyl (normal)
isopropyl (y-shape)
isobutyl (y-shape)
 
sec-butyl (2nd C)
 
tert-butyl (t-shape)
 

Alkanes

Contain only single bonds between C atoms
General chemical formula
CnH2n+2 (n = whole number)
Odour
Odourless
Polarity
Non-polar (only C-H bonds)
Solubility in water
Slightly soluble
Boilin­g/m­elting point
Depends on length of parent C chain (more C = BP, less C = BP)

Alkenes

Contain at least one double bond between C atoms
General chemical formula
CnH2n (n = whole number)
Odour
Almost odourless
Polarity
Non-polar (only C-H bonds)
Solubility in water
Slightly soluble
Boilin­g/m­elting point
Depends on length of parent C chain (more C = BP, less C = BP)

Alkynes

Contain at least one triple bond between C atoms
General chemical formula
CnH2n-2 (n = whole number)
Odour
Almost odourless
Polarity
Non-polar (only C-H bonds)
Solubility in water
Slightly soluble
Boilin­g/m­elting point
Depends on length of parent C chain (more C = BP, less C = BP)

Cycloalkyl

Alkane­/al­ken­e/a­lkyne where the C atoms are joined in a ring shape
General chemical formula
C2H2n (cycloalkane)
C2H2n-2 (cycloalkene)
C2H2n-4 (cycloalkyne)
(n = whole number)
Odour
Odourless/almost odourless
Polarity
Non-polar (only C-H bonds)
Solubility in water
Slightly soluble
Boilin­g/m­elting point
Depends on length of parent C chain (more C = BP, less C = BP)

Alcohols

Any compound that contains a hydroxyl (R(-OH­)-R') group
General chemical formula
CnH2n-1OH (n = whole number)
Odour
Slightly pungent
Polarity
Polar (between O-H bonds); longer C chains decrease in polarity
Solubility in water
Very soluble; longer C chains decrease solubility
Boilin­g/m­elting point
Depends on length of parent C chain (more C = BP, less C = BP)

Aldehy­des­/Ke­tones

Any compound that contains a carbonyl (R-C(=­O)-R') group
Aldehydes have the carbonyl group at the first and/or last C atom of the molecule
Ketones have the carbonyl group in the middle C atom(s) of the molecule
General chemical formula
CnH2nO (n = whole number)
Odour
Pungent (aldehyde)
Sweet (ketone)
Polarity
Polar (between C=O bonds); longer C chains decrease polarity
Solubility in water
Very soluble; longer C chains decrease solubility
Boilin­g/m­elting point
Very high, increases with length of parent C chain (more C = BP, less C = BP)

Carboxylic Acids/­Esters

Any compound that contains a carboxyl (R-C(=­O)-­O-R') group
Carboxylic acids have the carboxyl group at the first and/or last C atom of the molecule
Esters have the carboxyl group in the middle C atom(s) of the molecule
General chemical formula
CnH2nCOOH (n = whole number)
Odour
Unpleasant (carbo­xylic acid)
Pleasant (ester)
Polarity
Polar (between C=O bonds); longer C chains decrease polarity
Solubility in water
Very soluble; longer C chains decrease solubility
Boilin­g/m­elting point
Very high, increases with length of parent C chain (more C = BP, less C = BP)

Ethers

Any compound that contains an alkoxy (R-O-R') group
General chemical formula
CnH2n+2O (n = whole number)
Odour
Slightly pungent
Polarity
Polar (between C-O bonds); longer C chains decrease polarity
Solubility in water
Very soluble; longer C chains decrease solubility
Boilin­g/m­elting point
Depends on length of parent C chain (more C = BP, less C = BP)

Amines­/Amides

Any compound that contains a N atom in a carboxyl or carbonyl group
Amines have N atoms in a carbonyl group(s) (R-C(-­N(-­R')­-R")­-R'­")
Amides have N atoms in a carboxyl group(s) (R-C(=­O)-­N(-­R')­-R")
General chemical formula
CnH2n-1NO (n = whole number)
Polarity
Polar (between C=O, C-O and C-N bonds); longer C chains decrease polarity
Solubility in water
Very soluble; longer C chains decrease solubility
State @ SATP
Depends on length of parent C chain (more C = more solid, less C = more gas)
 

Interm­ole­cular Forces (IMFs)

Forces that occur between molecules
Influence the physical properties of a substance
Weaker than intramolecular forces (forces within molecules)
3 main types:
London Dispersion Forces (LDF)
Very weak forces that exist in all atoms/­mol­ecules caused by temporary charges due to e¯ shifts; become stronger with more e¯
Dipole- Dipole
Attraction between opposite charges of polar molecules;
main reason for difference in meltin­g/b­oiling points
Hydrogen bonding
Strong dipole­-dipole forces with H atoms covalently bonded with an N, O or F atom
Strength of forces: (weakest) LDF Dipole­-dipole H-bonding (stron­gest)

Combustion Reactions

All hydroc­arbons burn with oxygen gas (alkan­es/­alk­ene­s/a­lky­nes­/al­cohols)
Combustion of hydroc­arbon
CxHy + O2 CO2 + H2O
Combustion of alcohol
CxHyOH + O2 CO2 + H2O

Elimin­ation Reactions

Take away 2 atoms to form double bond or H2O
Also called conden­sat­ion­/de­hyd­ration reactions
Elimin­ation of haloalkyl
CxHyXz + [strong base] CxHy-1 + [halogen (X) salt] + H2O
Elimin­ation of alcohol
CxHyOH [conc acid] CxHy-1 + H2O

Substi­tution Reactions

Replace one atom with another
Substi­tution reaction
CxHy + X2 [heat/­pre­ssure] CxHy-1X + HX
Benzene rings
Benzene does not have true double bonds, so only substi­tution reactions can be performed
Benzene substi­tution
C6H6 + X2 C6H5X + HX
Benzene halide substi­tution
C6H5X + X2 C6H4X2 + HX
Halogen in benzene halide reactions forms product meta position only (1,3-[­X]b­enzene)

Addition Reactions

Add atoms across double­/triple bond
Alkene­s/a­lkynes are nucleo­philes (they like to give up e_)
Hydroh­alo­gen­ation
CxHy + HX CxHy+1X
Haloge­nation
CxHy + X2 CxHyX2
Hydrog­enation
CxHy + H2 CxHy+2
Hydration
CxHy + H2O
CxHy+1OH
Markov­nikov's Rule: "the rich get richer­"
The H atom of water/­hyd­rogen gas/hy­drogen halide will always bond with the C atom that already had more H atoms bonded to it in an addition reaction

Redox Reactions

Oxidation
C atoms will form more bonds to O atoms
Occurs when an organic compound reacts with an oxidizing agent (usually KMnO4/K2Cr2O7)
Oxidation of primary alcohol
CxHyOH [O] CxHy-1O (aldehyde)
Oxidation of secondary alcohol
CxHyOH [O] CxHy-1O (ketone)
Oxidation of tertiary alcohol
CxHyOH [O] NO RXN
Oxidation of aldehyde
CxHyO + H2O [O] CxHy-1OH + H2 (carboxylic acid)
Reduction
C atoms will form fewer bonds to O atoms
Occurs when an organic compound reacts with an reducing agent (usually H2/LiAlH4)
Hydrog­enation (reduction of aldehyde)
CxHyO + H2 [H] CxHy+1OH (primary alcohol)
Hydrog­enation (reduction of ketone)
CxHyO + H2 [H] CxHy+1OH (secondary alcohol)

Esterification/Hydrolysis of Esters

Esteri­fic­ation
Conden­sation reaction (forms H2O)
Catalyzed by concen­trated H2SO4 and high heat
Esteri­fic­ation
CxHyCOOH + CxHyOH [H2SO4] C2xH2yCO2 + H2O
Hydrolysis of Esters
Reverse reaction to esteri­fic­ation
Hydro = water, lysis = break
Hydrolysis of ester
C2xH2yCO2 + H2O [H2SO4] CxHyCOOH + CxHyOH
Remember: Ester is a party girl; she drank some alcohol and did some acid

Synthe­sis­/Hy­dro­lysis of Amides

Synthesis of Amides
Conden­sation reaction (forms H2O)
Synthesis of amide
CxHyCOOH (carbo­xylic acid) + CxHyNH2 (amine) CxHyONH2 (amide) + H2O
Hydrolysis of Amides
Reverse reaction to synthesis
Hydrolysis of amide
CxHyONH2 (amide) + H2O CxHyCOOH (carbo­xylic acid) + CxHyNH2 (amine)

Synthesis of Amines

Amines can be made from haloalkyls using ammonia as a starting reactant
Synthesis of primary amines
CxHxX + NH3 CxHyNH2 + HX
Synthesis of secondary amines
CxHxX + CxHyNH2 C2xH2yNH + HX
Synthesis of tertiary amines
CxHxX + C2xH2yNH C3xH3yN + HX

Polymers

Large molecules that are composed of many repeated subunits called monomers
Created through polyme­riz­ation
Examples include plastics, DNA, and proteins
Unique physical properties - checmi­cally unreactive, flexible/mouldable/stretc­hable
Polyme­riz­ation (addition - chain reaction of alkene)
CxHy + CxHy+ CxHy+ ... [CxHy]n
Polyme­riz­ation (conde­nsation with alcohol - polyester)
HOCxHyOH + HOOCCxHyCOOH + ... [O2CCxHyO2CxHyO2]n
Polyme­riz­ation (conde­nsation with alcohol - polyamide)
H2NCxHyNH2 + HOOCCxHyCOOH + ... [NOCCxHyO2CxHyON]n
Polyme­riz­ation (conde­nsa­tion) need the reacting functional group(s) to be on both sides of the monomer(s) to be able to complete the chain reaction (-dioic acid, -diol, -diamine)
                           
 

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  • Published: 23rd January, 2018
  • Last Updated: 29th December, 2018
  • Rated: 5 stars based on 3 ratings

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