Transcript Saturated hydrocarbons

VII. Organic
Organic compounds contain
carbon atoms which bond to
one another in chains, rings,
and networks to form a variety
of structures. Organic
compounds can be named
using the IUPAC system.
Hydrocarbons are compounds
that contain only carbon and
hydrogen.
Saturated hydrocarbons single carbon-carbon bonds.
Unsaturated hydrocarbons at
least one multiple carbon-carbon
bond.
Homologous series of hydrocarbons:
 Saturated hydrocarbons  Unsaturated hydrocarbons
– Alkanes
– Contain at least one double
or triple bond
• Only single bonds
– Alkenes
between carbons
• Contain one double bond
• Name ends in
• Name ends in ___ene
___ane
• General formula CnH2n
• General formula
CnH2n+2
– Alkynes
• Contain one triple bond
• Methane CH4
Ethane C2H6
• Name ends in ___yne
• General formula CnH2n-2
Table P gives the prefix used to
name the first 10 hydrocarbons in
an homologous series.
Table Q gives the general formula and
examples (name and structure) of the
homologous series of hydrocarbons.
Regents Question: 06/03 #24
Which element has atoms that can form single,
double, and triple covalent bonds with other
atoms of the same element?
(1) hydrogen
(2) oxygen
(3) fluorine
(4) carbon
The prefix of the name tells you how many
carbons in the chain.The suffix tells you the
type of hydrocarbon.
Example
Number
of
Carbons
Prefix
1
Meth
2
Eth
3
Prop
4
But
5
Pent
Alkane
CnH2n+2
Methane
CH4
Ethane
C2H6
Propane
C3H8
Butane
C4H10
Pentane
C5H12
Alkene
CnH2n
Ethene
C2H4
Propene
C3H6
Butene
C4H8
Pentene
C5H10
Alkyne
CnH2n-2
Ethyne
C2H2
Propyne
C3H4
Butyne
C4H6
Pentyne
C5H8
Regents Question: 06/03 #21
Which hydrocarbon is saturated?
(1) propene
(2) ethyne
(3) butene
(4) heptane
Alkanes are saturated hydrocarbons.
A structural formula show the
way the atoms are arranged.
 Methane
Ethane
H
H
C
H
H
H
H
H
C
C
H
H
Each line represents a
covalent bond - a shared
pair of electrons.
H
A structural formulas show the
way the atoms are arranged.
 propene
H
H
H
C
C
H
 ethyne
H
C
The double bonds makes
this hydrocarbon an alkene
C
H
C
H
H
The triple bonds makes this
hydrocarbon an alkyne
Regents Question: 01/03 #13
The empirical formula of a compound is CH2 Which
molecular formula is correctly paired with a
structural formula for this compound?
Chains of carbons can be
branched
 A carbon group connected to a chain is
called an alkyl group.
 To name the alkyl group, use the prefix for
the number of carbons and add yl.
-CH3
-C2H5
H
H
H
C
H
H
C
H
Methyl
H
C
H
Ethyl
Carbon always has 4 bonds.
 Hydrogen always has 1 bond
 Oxygen always has 2 bonds
 Nitrogen always has 3 bonds
C
or
H
O
C
or
or
O
C
N
Regents Question: 08/02 #42
Which structural formula is incorrect?
Carbon always
has four bonds.
Naming hydrocarbons with alkyl
groups:
 Find the longest continuous chain of
carbons. This is the backbone. Find the
name of the backbone.
 Find the name of the alkyl group (or groups)
attached to the backbone.
 Name the alkyl group and then the name of
the backbone.
 Use a number to indicate which carbon the
alkyl group is attached to if necessary.
Find the name of this
hydrocarbon.
H
H
H
H
H
C
H
H
H
H
C C C C C C H
1 6 2 5 3 4 4 3 5 26 1
H H H H H H
Find the longest chain
3- methyl hexane
Find the alkyl group
Counting from each direction find the carbon where
the alkyl group is attached (the lower number)
The longest chain does not have
to be drawn straight.
H
H
C
H
H
C
H
H
H
H
H H
C
C
C
C
C
H
H
H
H
H
3-methylhexane
H
Chains of carbons can form rings
 Use a prefix cyclo when a ring is formed
 To make a ring, two Hydrogen atoms are
removed
Cyclopentane is a 5
carbon ring with all
single bonds.
Organic acids, alcohols, esters,
aldehydes, ketones, ethers, halides,
amines, amides, and amino acids
are categories of organic molecules
that differ in their structures.
Functional groups impart distinctive
physical and chemical properties to
organic compounds.
Reference Table R lists all the
functional groups.
Reference Table R Cont’d.
Regents Question: 06/03 #44
Given the formulas of four organic compounds:
Which pair below contains an alcohol and an
acid?
(1) a and b
(3) b and d
(2) a and c
(4) c and d
Naming Halocarbons (-X)
 Halocarbons (or halides) have a halogen (F, Cl,
Br, I) in place of a hydrogen
 Name the halogen first (fluoro, chloro, bromo,
iodo) then name the alkane
 If there are more than 2 carbons in the chain, use a
number to indicate which carbon the –X group is
attached to. (Number from the direction that gives
the smallest number)
H
1-chloropropane
2-bromobutane
H
H
Cl
H
Br
H
H
C
C
C
C
C
C
C
H
H
H
H
H
H
H
H
H
H
Naming Alcohols (-OH)
 Alcohols have the hydroxyl group -OH
 The prefix is the number of carbons in the longest
chain
– Name the alkane and drop the letter e
 The suffix is ol
 If there are more than 2 carbons in the chain, use a
number to indicate which carbon the –OH group is
attached to. (Number from the direction that gives
the smallest number)
1-propanol
H
H
H
OH
C
C
C
H
H
H
2-propanol
H
H
H
OH
H
C
C
C
H
H
H
H
Regents Question: 08/02 #20
Which compound is an alcohol?
(1) propanal
(2) ethyne
(3) butane
(4) methanol
Naming Ethers (-O-)
 Ethers have an Oxygen in the chain of carbons
 Name the alkyl groups on either side of the O
that is in the chain
 Write them by number of carbons (least to most)
 If both alkyl groups are the same it is named
once with the prefix DI in front of it.
Methyl ethyl ether
H
H
H
C
C
H
H
Dimethyl ether
H
O
C
H
H
H
H
H
C O C
H
H
H
Naming Aldehydes (-CHO)
 Aldehydes have a double bonded Oxygen
on the last carbon in the chain.
 Name the alkane, drop the e and add __al
propanal
H
H
H O
C
C C
H
H
methanal
O
H
H
C
H
Naming Ketones (-CO-)
 Ketones have a double bonded Oxygen on a
carbon in the middle of the chain. (Not the last
carbon)
 Name the alkane, drop the e and add __one
 If there are more than 4 carbons in the chain, use a
number to indicate the location of the =O
butanone
H
3-pentanone
H
H
O H
C
C C
C H
H
H
H
H
H
H
O H
H
C
C
C
C
C H
H
H
H
H
Naming Organic Acids (-COOH)
 Acids have a double bonded Oxygen and an
–OH on the last carbon in the chain.
 Name the acid, drop the e and add __oic
acid
This is OH and not HO…the
Carbon is bonded to the O
Propanoic acid
H
H
H
C
C C
H
H
Pentanoic acid
O
OH
O
H
H
H
H
HO C
C
C
C
C
H
H
H
H
H
Naming Esters
 Esters are made by the dehydration
synthesis of an alcohol (–OH) and an
organic acid (-COOH)
 Cut the compound at the –O Name the alcohol then the acid with an
“oate” ending.
ethanol
H
H
H
C
C
H
H
Pentanoic acid
OH
O
H
H
H
H
HO C
C
C
C
C
H
H
H
H
H
Naming Esters
ethanol
H
H
C
H
Pentanoic acid
H
C
O
H
H
H
H
HO C
C
C
C
C H
H
H
H
H
OH
H
H2O
Ethyl pentonoate
H
H
H
C
C
H
H
O
O
H
H
H
H
C
C
C
C
C H
H
H
H
H
Naming Amines (-NH2)
 Amines have a nitrogen bonded to the carbon
chain. The nitrogen may have two, one or no
hydrogen atoms bonded to it.
 Name the alkane, drop the e and add __amine
 If there are more than two carbon atoms, use a
number to indicate which carbon the N is attached
to.
ethanamine
H
H
H
C
C NH2
H
H
2-Pentanamine
H NH2 H
H
H
H C
C
C
C
C
H
H
H
H
H
H
Name the folowing:
H
H
C
O
C
H
H
H
O
C
C
OH
H
H
C
C C
H
H
H H
C
C
C N
H
H
H
O H
H
H
C
C
C
H
H
H
3-hexanone
H
1-Propanamine
H
H
H
H
H C
C
C
C
H
H 2-butene H
Ethanal
H
H
Ethanoic acid
H
H
H
H
H
H
OH H
H H
H C
C
C
C
C H
H
H
H
H
H
2-pentanol
Regents Question: 06/02 #17
Which compound is classified as a hydrocarbon?
(1) Ethane
(2) Ethanol
(3) chloroethane
(4) ethanoic acid
Regents Question: 06/02 #48
Which pair of compounds are alcohols?
Regents Question: 01/03 #49
Which type of organic compound is represented
by the structural formula shown below?
(1) aldehyde
(2) alcohol
(3) ether
(4) ester
Isomers of organic
compounds have the same
molecular formula but different
structures and properties.
Pentane C5H12
H
H
H
H
H
H
C
C
C
C
C
H
H
H
H
H
Methylbutane C5H12
H
H
H
H
H
H
C
C
C
C
H
H
H
H
C
H
H
H
Examples of isomers:
1-butanol (C4H9OH)
diethyl ether (C2H5OC2H5)
4 Carbon, 10 Hydrogen, 1 Oxygen
propanal (C2H5CHO)
2-propanone (CH3COCH3)
3 Carbon, 6 Hydrogen, 1 Oxygen
Isomers have the same chemical formulas but different
structural formulas.
Regents Question: 06/03 #25
Which compound is an isomer of pentane?
(1) butane
(2) propane
(3) methyl butane
(4) methyl propane
Regents Question: 06/02 #19
Which formula is an isomer of butane?
Regents Question: 08/02 #55
Given the structural formula for butane:
Draw the structural formula for an isomer of butane.
H
H
H
H
C
C
C
H
H
H
C
H
H
H
Regents Question: 01/03 #18
Which compound has an isomer?
In a multiple covalent bond,
more than one pair of
electrons are shared between
two atoms.
Alkenes have one double bond
H
H
C
C
H
Ethene C2H4
H
Alkynes have one triple bond
H
C
C
H
Ethyne C2H2
Saturated- only single bonds.
Unsaturated-organic compounds contain at
least one double or triple bond.
Alkenes and Alkynes are unsaturated.
By breaking the multiple bond in alkenes and
alkynes, more hydrogen atoms can be added
Alkanes are saturated.
Alkanes do not have multiple bonds,
therefore, they already have as many
hydrogen atoms as they could possibly hold.
Regents Question: 01/03 #25
In saturated hydrocarbons, carbon atoms are
bonded to each other by
(1) single covalent bonds, only
(2) double covalent bonds, only
(3) alternating single and double covalent bonds
(4) alternating double and triple covalent bonds
Types of organic reactions
include:
•addition
•substitution
•polymerization
• esterfication
•fermentation
•saponification
•combustion.
Organic Reactions-Addition
 Addition
– H2, Cl2, Br2, HCl, HBr is added to an
unsaturated hyrdrocarbon. Both atoms are
added to where the double (or triple) bond was
located.
– Key to look for – Unsaturated hydrocarbon
reactant and one product.
H
H
C
H
C
+ Cl2
H
H
Cl
Cl
C
C
H
H
H
Organic Reactions-Addition Cont’d
Addition of hydrogen H2 Can be used to saturate
and unsaturated hydrocarbon. It uses a catalyst
such as platinum (Pt)
H
H
C
H
C
+ H2
H
H
H
C
C
H
H
Pt
H
H
Regents Question: 01/03 #26
Which formula correctly represents the product
of an addition reaction between ethene and
chlorine?
(1) CH2Cl2
(2) CH3Cl
(3) C2H4Cl2
(4) C2H3Cl
Organic Reactions-Substitution
 Substitution
– A halogen is reacted with a saturated
hydrocarbon. One of the halogen atoms
substitutes one of the hydrogen atoms.
– Key to look for – Saturated hydrocarbon
reactant and two product.
H
H
H
C
C
H
H
H + Cl2
UV
H
H
Cl
C
C H + HCl
H
H
Organic Reactions-Polymerization
 Polymerization – joining many small
molecules together to form a large molecule
– A single unit is called a monomer
– Many monomers are bonded together to form a
polymer
– Polymers can be natural or artificial
Natural Polymers
Protein
Rubber
Cellulose
Artificial Polymers
Polyester
Nylon
Styrofoam
Regents Question: 06/02 #49
The process of joining many small molecules
into larger molecules is called
(1) neutralization
(2) polymerization
(3) Saponification
(4) substitution
Regents Question: 06/03 #45
Which type of reaction is represented by the equation
below?
Note: n and n are very large numbers equal to about
2000.
(1) Esterification
(3) saponification
(2) fermentation
(4) polymerization
Organic Reactions-Esterification
 Esterification – making an ester by
combining an alcohol with an organic acid
H
H
H
H
C
C
H
H
H
H
C
C
H
H
OH
+
HO
O
H
C
C
H
H
O
O
H
C
C
H
H
+
H2O
Naming Esters (-COOC-)
 Esters have a double bonded Oxygen and an
–O– bonded to another carbon.
 Name the alkyl group that came from the
alcohol. Name the acid but drop __ic acid
and replace it with ate.
Propanoic acid + pentanol
Pentyl propanoate + water
Propanoic acid
H
H
H
C
C C
H
H
1-Pentanol
O
OH
H
H
H
H
H
HO C
C
C
C
C
H
H
H
H
H
H
Making an ester by removing
water from an acid and an alcohol
Propanoic acid
H
1-Pentanol
H
H
O
H
H
H
H
H
C
C C
OH HO C
C
C
C
C H
H
H
H
H
H
H
H
Pentyl propanoate
Name the ester: Methyl ethanoate
H O
H
C
H
Ethanoate
Acid
C
H
O
C
H
H
Alcohol
Methyl
Determine which side was the alcohol and which
side was the acid by drawing a line through the
oxygen in the chain. The side with the double
bonded O was the acid.
Alcohol will make you yl if you ate the acid.
Regents Question: 08/02 #56
Given the ester: ethyl butanoate
a. Draw the structural formula for this
ester.
b. Determine the gram formula mass of
this ester.
C 6 x 12 = 72
H H H O
H H
H
C
C
C
H
H
H
C
O C
H
C H
O 2 x 16 = 32
H
H 12 x 1 = 12
Even if you got the structure wrong but you got the correct
mass for the structure you drew, you got one point.
116 g
Amides (-CON) are made by
reacting an organic acid with
ammonia or with an amine.
H
H
O
C
C
H
N
H
H
From ammonia
(NH3)
H
H
O
C
C
H
H
N
C
H
H
H
From amine
(CH3NH2)
Naming Amides (-CON-)
 Amides have a double bonded Oxygen and
a Nitrogen.
 Name the alkyl group that came from the
amine. Name the acid but drop __oic acid
and replace it with amide.
Propanoic acid + 1-pentanamine
Pentyl propanamide + water
Propanoic acid
H
H
H
C
C C
H
H
1-Pentanamine
O
OH
H
H
H
H
H
H2N C
C
C
C
C
H
H
H
H
H
H
Making an amide by removing
water from an acid and an amine
Propanoic acid
H
H
H
O
C
C C
H
H
OH
1-Pentanamine
H
H
H
H
H
HN C
C
C
C
C
H H
H
H
H
H
Pentyl propanamide
H
Amino acids have both an amine
group and an acid group.
An amino acid is a compound that has an amine group
on one side and an acid group on the other.
HO
O
R
C
C N
H
H
H
R is the only part that changes in different
amino acids.
Proteins are polymers of amino
Remove water
HO
O
R
O
R
C
C N
C
C
H H
N
H H
H HO
O
R
C
C N H
H H
Organic Reactions-Fermentation
 Fermentation – yeast and bacteria can make
ethanol and carbon dioxide by breaking down
sugar using an enzyme.
C6H12O6
Enzyme
2C2H5OH + 2CO2
– The alcohol can be used to make beer and wine,
– The carbon dioxide can be used to make bread rise or
make the bubbles in beer and champagne.
Organic Reactions-Saponification
 Saponification is a reaction in which a lipid
(fat or oil) is used to make soap.
Organic Reactions-Combustion
 Combustion
– Burning
– Combining with oxygen to produce carbon
dioxide and water
Burning Methane
CH4 + 2O2
Burning Octane
2C8H18 +25O2
Burning Ehtanol
C2H5OH + 3O2
CO2 + 2H2O
16CO2 + 18H2O
2CO2 + 3H2O
Regents Question: 08/02 #21
In which reaction is soap a product?
(1) addition
(2) substitution
(3) Saponification
(4) polymerization