Organic Chemistry Review

ORGANIC CHEMISTRY Organic Chemistry is the study of carbon and most carbon compounds. Elemental carbon is found in nature as a solid. However, this solid can make many different forms, such as diamond and graphite. Carbon’s properties make possible an incredible variety of compounds, many of which form the basis for life itself. In this unit you will be introduced to the wide variety of organic compounds and the types of reactions they undergo.

I. Bonding of Carbon Atoms A. Carbon has a unique ability to form many different compounds - This is based on the tendency of carbon atoms to ________________ bond with other carbon atoms and form ____________.

- One carbon atom can form a maximum of __________ covalent bonds Un-bonded carbon (ground state)

Bonded carbon

C

C

B. Properties of Carbon Bonds 1. Covalently bonded to each other 2. Generally have _________ melting points and ________ boiling points 3. _________ conductors of heat and electricity 4. Most are ____________ and tend to dissolve in non-polar solvents 5. _____________ to react C. The Bonding Behavior of Carbon 1. Carbon atoms share electrons to form _________________________ - a single line is often used to represent the pair of shared electrons - When one pair of electrons (2 electrons) is shared between 2 carbon atoms, the bond is called a ________________________ - When carbons share two pairs of electrons (or four electrons) they form a ________________________ - Carbons sharing three pairs of electrons (6 electrons) form a __________________

D. Molecular Formula vs. Structural Formulas vs. Condensed Structural Formula 1.) Molecular Formula – shows the type and the # of atoms involved Examples: C4H10 C2H4 C8H18 2.) Structural Formula – shows the arrangement of atoms and bonds in a molecule 2-dimensional

vs.

3-dimensional

3.) Condensed Structural Formula – shows the arrangement of atoms in a molecule, without including all the bonds between atoms Examples:

CH3CH2CH=CHCH3

CH3-(CH2)4-CH3

II. HYDROCARBONS A. Definition: Organic compounds that contain only atoms of _______ and ________.

B. Homologous series of compounds  _________________________________________________________ 1.) Alkanes 2.) Alkenes 3.) Alkynes

1.) Alkanes - Single bonds only between carbon atoms - Homologous series of ______________ hydrocarbon

2.) Alkenes - Chain of carbon atoms with one ____________ bond between C atoms - Homologous series of _________________ hydrocarbons - The double bond can be anywhere within the carbon chain - Alkenes are named by changing the – ane name to -ene

3.) Alkyne - Chain of carbon atoms with one ____________ bond between C atoms - Homologous series of _________________ hydrocarbons - The triple bond can be anywhere within the carbon chain - Alkynes are named by changing the – ane name to –yne

C. Naming Simple Hydrocarbons – Use Reference Table P & Q 1.) Determine the number of carbons in the chain 2.) Choose the appropriate prefix from Table P 3.) Determine the type of bonding found in the chain from Table Q (single, double or triple) 4.) Choose the suffix –ane, -ene or –yne for single, double or triple bonding respectively

Practice: 1.) Tell if the following are saturated hydrocarbons or unsaturated hydrocarbons (Hint: saturated = alkane; unsaturated = alkene or alkyne, use general formulas) a) C2H2 _______________

e) C2H2 _______________

b) C5H12 _______________

f) C7H14 _______________

c) C3H8 _______________

g) C7H16 _______________

d) C4H6 _______________

h) C6H10 _______________

2.) Name the following by determining what “General Formula” the formula given fits into from Table Q and choosing the proper prefix from Table P a) C2H2 _________________________

e) C2H2 _________________________

b) C5H12 _________________________

f) C7H14 ________________________

c) C3H8 _________________________

g) C7H16 ________________________

d) C4H6 _________________________

h) C6H10 ________________________

D. Drawing structural formulas when the Molecular Formula is given - 1st determine what “General Formula” the formula fits into (CnH2n+2, CnH2n, or CnH2n-2) - 2nd draw the carbon chain - 3rd insert the single bonds between carbon  include one double bond in the chain if it’s an alkene  include one triple bond in the chain if it’s an alkyne th -4 add the hydrogen atoms to each carbon ensuring that each carbon has 4 bonds a) C3H6 b) C5H8 c) C4H10

d) C2H6 e) C2H2 f) C4H8 E. Drawing structural formulas when the Name of the Organic Compound is given - 1st determine how many carbons are in the chain based on the prefix and Table P - 2nd draw the carbon chain - 3rd look at the ending of the name to see if it ends in –ane, -ene or –yne - 4th insert the single bonds between carbon atoms if it ends in –ane

- if there is a number in front of the name (ex. 2-butene) that number tells you after which carbon to place the double (-ene ending) or triple bond (-yne ending) th -5 add hydrogen atoms to each carbon ensuring that each carbon has 4 bonds Example 1: a) 2-butene =

Example 2: b) 2-hexyne =

Example 3: c) nonane =

prefix but- means 4 carbon chain suffix -ene means there is a double bond the #2 means after the 2nd carbon insert the double bond; all remaining bonds between carbons get single bonds insert hydrogen atoms to give each carbon four bonds

prefix hex- means 6 carbon chain suffix -yne means there is a triple bond the #3 means after the 3rd carbon insert the triple bond; all remaining bonds between carbons get single bonds insert hydrogen atoms to give each carbon four bonds

prefix non- means 9 carbon chain suffix -ane means there is all single bonds insert hydrogen atoms to give each carbon four bonds

Formula

General Formula

ORGANIC CHEMISTRY WORKSHEET Series Structural Formula Condensed Structural Formula

C5H12

CnH2n+2

Alkane

Molecular

CH3CH2CH2CH2CH3

Name of Compound Pentane

3- Heptyne

CH3CH2CH3

CH3CH=CHCH2CH3

C9H20

Molecular Formula

General Formula

Series

Structural Formula

Condensed Structural Formula

Name of Compound

1-Octene

C8H18

C9H18

CH3–(CH2)4-CH3

F. Naming Branched-Chain Hydrocarbons - There are also hydrocarbons chains which have smaller carbon chains branching off the main chain of carbon atoms

“branches” - These organic compounds are named like we learned before, except we must now add in the part to tell us the location and the type of branch that forms off the main chain 1) When straight-chain hydrocarbons have attached groups these also must be named.

These groups are called ______________ groups. The group names end in –yl, and we use the prefix from Table P to tell us how many carbons there are. * The CH3- group off the main chain is called a methyl group. * The CH3-CH2 group off the main chain is called an ethyl group. * The CH3-CH2-CH2 group off the main chain is called an propyl group 2) We also need to show the location of the “branch” off the main chain, so we give the ________________ of the carbon atom it falls on. To do this, we number the carbons in the chain, making sure that the branch falls on the lowest possible number.

Example 1:

- main chain of carbons = 4 carbons (but-) - on the 2nd carbon is a CH3 group = methyl - we first list the number the group is on, then the name the “branched” group, then end with the main chain name 2–methyl–butane

Example 2:

H

- main chain of carbons = 7 carbons (hept-) - on the 3rd carbon is a CH3CH2 group = ethyl - we first list the number the group is on, then the name the “branched” group, then end with the main chain name

3–ethyl–heptane Example 3:

H 2,4-dimethyl–hexene

- main chain of carbons = 6 carbons (hex-) - on the 2nd & 4thcarbon is a CH3- group = methyl - we first list the number the groups are on, then the name the “branched” group, then end with the main chain name

Practice Drawing and Naming Branched – Chain Hydrocarbons: STRUCTURAL FORMULA

NAME

3-ethyl-3-methyl-hexane

2-methyl-3-ethyl heptane

1,3-diethylpentane

III. FUNCTIONAL GROUPS Although hydrocarbons are the most basic organic compounds, many other compounds form when other atoms replace one or more hydrogen atoms in a hydrocarbon. These atoms or groups of atoms are called functional groups. They give the compounds distinctive chemical and physical properties.

1. HALIDES – ________________________________________________________ Compound is called a ______________________ Examples of Halocarbons:

Naming/Drawing a Halocarbon 1.)

2.) 1,1-dichlorobutane

3.)

4.)

5.)

6.) 1-chloro-2-fluoropentane

7.)

8.) 1,3-difluoro-2-iodohexane

2. ALCOHOLS - __________________________________________________________ The –OH groups is called the ___________________ group in organic chemistry Although the –OH group resembles the hydroxide ion of bases, it DOES NOT form an ion in water Examples of Alcohols

Classifications of Alcohols Classifications of Alcohols - Primary Alcohol - Secondary Alcohol

- Dihydroxy Alcohols

- Trihydroxy Alcohols

Naming/Drawing an Alcohol 1.)

2.) 2-propanol

3.)

4.) 3,3-hexandiol

5.)

6.) 2,4-heptanol

- Tertiary Alcohol

3. ALDEHYDES - _________________________________________________________ - the bond is called a __________________ group *this group is found on the END CARBON of a chain Examples of Aldehydes

Naming & Drawing Aldehydes 1.)

2.) hexanal

3.)

4.) pentanal

5.)

6.) nonanal

7.)

methanal

8.) octanal

4. KETONES - ___________________________________________________________ * The bond is called a _______________________ group *this group is found on the INTERIOR CARBON of a chain Examples of Ketones

Naming & Drawing Ketones 1.)

2.) 4-octanone

3.)

4.) 2-pentanone

5.)

6.) 3-heptanone

7.) 2-nonanone

5. ETHERS - ____________________________________________________________ * General formula is written _______________ to show the oxygen bridge between the two carbon chains Examples of Ethers

Naming & Drawing Ethers 1.)

2.) methyl propyl ether

3.)

4.) propyl ethyl ether

5.)

6.) methyl ethyl ether

7.)

ethyl butyl ether

6. ORGANIC ACID ______________________________________________________ Examples of Organic Acids

Naming & Drawing Organic Acids 1.)

2.) pentanoic acid

3.)

4.) butanoic acid

5.)

6.) hexanoic acid

7.) octanoic acid

7. ESTERS __________________________________________________________ -

General formula is written ______________ to show the oxygen bridge between the two carbon chains Esters are commonly formed from a reaction between a carboxylic acid and an alcohol

Examples of Esters

Naming & Drawing Esters 1.)

2.) ethyl ethanoate

3.)

4.) ethyl propanoate

8. AMINES - ____________________________________________________________ A derivative of ammonia: Examples of Amines

1.)

Naming & Drawing Amines

2.) 1-butanamine

3.) 2-propanamine

4.) 3-pentanamine

9. AMIDES - ______________________________________________________ - amines react with carboxylic acids to form amides A. Examples of Amides

10. AMINO ACIDS _________________________________________________ - like all organic acids, amino acids contain the group but also contain an amine group * The amine group ( ) is attached to the carbon atom that is adjacent to the acid group

B. Examples of Amino Acids

GLYCINE

IV. ISOMERS Definition:_______________________________________________________ _______________________________________________________________ Example: C4H10 – Butane

Example: C5H12 - Pentane

Structural isomers can also involve the position of a functional group and the position of a double or triple bond.

A. Position of a functional group: molecular formula = C3H7OH

B. Position of a double bond: molecular formula = C4H8

C. Position of a triple bond: molecular formula = C4H6

V. ORGANIC REACTIONS Organic Reactions generally occur more slowly than inorganic reactions. When covalently bonded substances react, they must first break relatively strong existing bonds before making new bonds. For this reason, the use of catalysts is a common practice. The types of organic reactions total that we will be covering are below.

1.) Substitution Reaction Replaces hydrogen (H) in the molecule with another element, such as a halogen. Other fragments of an alkane (called an alkyl group) can also be substituted for the hydrogen creating branched alkanes.

What to look for:

Reactant – one alkane Products – TWO of them: the substituted hydrocarbon and a small molecule called a by-product. **A HALOCARBON has been made (named for the halogen substitution.)

Example:

C4H10 + Cl2  C4H9Cl + HCl

2.) Addition Reaction Breaking or ADDING across the double or triple bond in the molecule with other elements, such as the halogens, to form a more saturated hydrocarbon (single bonds). Other fragments of an alkane called an alkyl group can also be added across the double or triple bond creating branched alkanes What to look for: Example:

Reactant – DOUBLE OR TRIPLE BOND (Alkene or alkyne) Product – ONE: the substituted hydrocarbon.

C5H10 + F2  C5H10F2

3.) Combustion Reaction Another name for burning…examples on Reference Table I What to look for:

Reactants – Hydrocarbon or alcohol and O2 Products – CO2 and H2O

Example:

4.) Fermentation Oldest known Organic Reaction to man!!! Makes buzz in booze What to look for:

Reactants: Glucose (C6H12O6), sometimes the catalyst zymase is written on top of the arrow Products: CO2 + Ethanol (C2H5OH)

Example:

5.) Esterification How the smell gets into smelly stickers…making fruity & minty compounds – esters – by dehydration synthesis What to look for:

Example:

Reactants – Organic Acid (R-COOH) & an Alcohol (R’-OH) Products – The ester link R-COO-R’ and H2O

HCOOH + CH3OH  HCOOCH3 + H2O CH3COOH + CH3OH  CH3COOCH3 + H2O

6.) Saponification 2nd oldest reaction to man… First four letters rearranged spells: ___________ This is what is made!!! (Reaction is the opposite of esterification) What to look for:

Example:

Reactants – Fat (a glycerol ester) + Base (NaOH or KOH) Products – Glycerol and soap (salt of the Organic Acid)

(C17H35COO)3C3H5 + 3 NaOH  3 C17H35COONa + C3H5(OH)3

7.) Polymerization – Addition & Condensation Reaction which makes GIANT molecules called POLYMERS by hooking together small molecules using a catalyst.

Polymer: “many parts” - extremely large molecules Man-made: Nylon, polyester, polyethylene, polystyrene Natural: Linen, silk, cotton, wool, cellulose (paper), protein, starches Monomer: “one part” – small molecules used to make the polymer, they are the building blocks of the polymer A. Addition Polymerization: Monomers are connected by breaking one of a double or triple bond to hook together What to look for: Example:

Reactants – double or triple bond: n C2H4 (n is a whole number) Products -(alkane)n-

n -CH2-  (-CH2-)n (where n = a whole number)

OR

B. Condensation Polymerization: monomers are connected by removing a water molecule (dehydration synthesis) What to look for: Example:

Reactants: Amino acids or dihydroxy alcohol & double Organic Acid Products: H2O & the Polymer