organic chemistry.....aim 4

what are the major types of organic reactions?

.....aim 3

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aims.....

 

HW From textbook “CHEMISTRY a Contemporary Approach”

 

Types of organic reactions include: addition, substitution, polymerization, esterification, fermentation, saponification, and combustion.

 

Addition reactions are reactions where unsaturated hydrocarbons react with atoms yielding a saturated hydrocarbon.

In halogenation an unsaturated hydrocarbon reacts with a halogen.

Example

H

 

 

 

 

 

H

 

 

 

 

 

 

 

 

 

 

 

Cl

 

Cl

 

 

 

 

 

\

 

 

 

/

 

 

 

 

 

 

 

 

 

 

 

 

|

 

|

 

 

 

 

 

 

C

=

C

 

 

+

 

Cl

—

Cl

 

---->

 

H

—

C

—

C

—

H

 

 

 

/

 

 

 

\

 

 

 

 

 

 

 

 

 

 

 

 

|

 

|

 

 

 

 

H

 

 

 

 

 

H

 

 

 

 

 

 

 

 

 

 

 

H

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ethene

 

 

chlorine gas

 

 

 

1,2-dichoroethane

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cl

 

Cl

 

 

 

 

 

 

 

 

 

 

 

 

 

Cl

—

Cl

 

 

 

 

 

 

|

 

|

 

 

 

 

H

—

C

≡

C

—

H

+

 

 

 

 

 

---->

 

H

—

C

—

C

—

H

 

 

 

 

 

 

 

 

 

 

 

Cl

—

Cl

 

 

 

 

 

 

|

 

|

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cl

 

Cl

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ethyne

 

 

chlorine gas

 

 

1,1,2,2-tetrachoroethane

 

In hydrogenation an unsaturated hydrocarbon reacts with hydrogen. Dehydrogenation reactions are the reverse of hydrogenation reactions. 

Example

H

 

 

 

 

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

H

 

H

 

 

 

\

 

 

 

/

 

 

 

 

 

 

 

platinum

 

 

 

|

 

|

 

 

 

 

C

=

C

 

 

+

 

H

—

H

 

---------->

 

H

—

C

—

C

—

H

 

/

 

 

 

\

 

 

 

 

 

 

 

 

 

 

 

 

 

 

|

 

|

 

 

H

 

 

 

 

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

H

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ethene

 

 

hydrogen gas

 

 

 

 

 

ethane

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

H

 

H

 

 

 

 

 

 

 

 

 

 

 

H

—

H

 

platinum

 

 

 

|

 

|

 

 

H

—

C

≡

C

—

H

+

 

 

 

 

 

---------->

 

H

—

C

—

C

—

H

 

 

 

 

 

 

 

 

 

H

—

H

 

 

 

 

 

 

 

 

|

 

|

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

H

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ethyne

 

 

hydrogen gas

 

 

 

 

 

ethane

Problems

1. What halocarbon is produced when ethene reacts with bromine gas?

2. Write the reaction that produces propane from propyne.

3. Write the reaction that produces 1,2-difluoroethane.

4. What halide is formed when 1 mole of ethyne reacts with 2 moles of I2?

 

Substitution reactions are reactions where one hydrogen atom of a saturated hydrocarbon is replaced by a halogen.

Example

 

 

H

 

H

 

 

 

 

 

 

 

 

 

 

H

 

H

 

 

 

 

 

 

 

 

 

|

 

|

 

 

 

 

 

 

 

 

 

 

|

 

|

 

 

 

 

 

 

 

H

—

C

—

C

—

H

+

Br

—

Br

---->

H

—

C

—

C

—

Br

+

H

—

Br

 

 

 

|

 

|

 

 

 

 

 

 

 

 

 

 

|

 

|

 

 

 

 

 

 

 

 

 

H

 

H

 

 

 

 

 

 

 

 

 

 

H

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ethane

 

bromine

 

1-bromoethane

hydrogen bromide

 

Problems

1. Write all the possible halides that could be produced by the reaction of propane with chlorine gas.

2. Write the reaction for the making of 2-iodobutane and hydrogen iodide.

 

In polymerization reactions monomers or single units are attached to each other to form long chains or polymers. Monomers have to have at least two functional groups, one at each end, so that an attachment can be accomplished.

Natural polymers are starch, cellulose, and proteins. Synthetic polymers are nylon, silicone, and polyethylene

In a condensation polymerization reaction monomers are bonded by a dehydration reaction (the removal of water)

Example

 

 

H

 

H

 

 

 

 

 

 

 

H

 

H

 

 

 

 

 

 

 

|

 

|

 

 

 

 

 

 

 

|

 

|

 

 

 

 

 

HO

—

C

—

C

—

OH

 

+

 

HO

—

C

—

C

—

OH

 

 

 

 

 

|

 

|

 

 

 

 

 

 

 

|

 

|

 

 

 

 

 

 

 

H

 

H

 

 

 

 

 

 

 

H

 

H

 

 

 

 

 

monomer

monomer

 

 

 

 

 

 

 

 

↓

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

H

 

H

 

 

 

H

 

H

 

 

 

 

 

 

 

 

 

 

 

|

 

|

 

 

 

|

 

|

 

 

 

 

 

 

 

 

 

HO

—

C

—

C

—

O

—

C

—

C

—

OH

+

H2O

 

 

 

 

|

 

|

 

 

 

|

 

|

 

 

 

 

 

 

 

 

 

 

 

H

 

H

 

 

 

H

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

polymer (dimer)

 

 

 

 

 

 

 

 

 

 

 In an addition polymerization reaction monomers of unsaturated compounds are bonded by "opening" a double bond in the carbon chain.

Example

 

 

H

 

H

 

 

 

 

 

 

 

[

 

H

 

H

 

]

 

 

 

|

 

|

 

 

catalyst

 

 

|

 

|

 

 

n

 

C

=

C

 

 

---------->

 

—

C

—

C

—

 

 

 

|

 

|

 

 

 

 

 

 

 

 

|

 

|

 

n

 

 

H

 

H

 

 

 

 

 

 

 

 

H

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 ethene (ethylene)

 

 

 

 

polyethylene

Problems

1. Write the reaction for the production of HOCH2CH2CH2CH2OCH2CH2CH2CH2OH

2. Teflon is made from the monomer 1,1,2,2-tetrafluoroethene. Write the reaction for the making of teflon.

 

Esterification reactions are the reactions of organic acids with alcohols yielding esters and water. The ester link is R1-COO-R2. Esters have pleasant odors. The aromas of many fruits, flowers, and perfumes are due to esters.

Example

 

 

H

 

 

 

 

 

 

 

O

 

H

 

H

 

H

 

H

 

 

 

 

 

 

|

 

 

 

 

 

 

 

| |

 

|

 

|

 

|

 

|

 

 

 

 

H

—

C

—

OH

 

 

 

HO

—

C

—

C

—

C

—

C

—

C

—

H

 

 

 

 

|

 

 

 

 

 

 

 

 

 

|

 

|

 

|

 

|

 

 

 

 

 

 

H

 

 

 

 

 

 

 

 

 

H

 

H

 

H

 

H

 

 

 

 

 

 

 

 

 

 

↓

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

methanol

 

 

 

pentanoic acid

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

H

 

 

 

O

 

H

 

H

 

H

 

H

 

 

 

 

 

 

 

 

 

 

|

 

 

 

| |

 

|

 

|

 

|

 

|

 

 

 

 

 

 

 

 

H

—

C

—

O

—

C

—

C

—

C

—

C

—

C

—

H

 

+

 

H2O

 

 

|

 

 

 

 

 

|

 

|

 

|

 

|

 

 

 

 

 

 

 

 

 

 

H

 

 

 

 

 

H

 

H

 

H

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

methyl pentanoate

 

 

 

 

 

 

 

Example

 

 

H

 

 

 

 

 

O

 

 

 

 

 

 

H

 

 

 

O

 

 

 

 

 

 

 

|

 

 

 

 

 

| |

 

 

 

 

 

 

|

 

 

 

| |

 

 

 

 

 

H

—

C

—

OH

 

HO

—

C

—

R

 

 

H

—

C

—

O

—

C

—

R

 

 

 

 

 

|

 

 

 

 

 

 

 

 

 

 

 

 

|

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

O

 

 

 

 

 

 

 

 

 

O

 

 

 

 

 

 

 

 

 

 

| |

 

 

 

 

 

 

 

 

 

| |

 

 

 

H

—

C

—

OH

+

HO

—

C

—

R

---->

H

—

C

—

O

—

C

—

R

+

3 H2O

 

 

|

 

 

 

 

 

 

 

 

 

 

 

 

|

 

 

 

 

 

 

 

 

 

 

 

 

 

 

O

 

 

 

 

 

 

 

 

 

O

 

 

 

 

 

 

 

 

 

 

 

| |

 

 

 

 

 

 

 

 

 

| |

 

 

 

 

H

—

C

—

OH

 

HO

—

C

—

R

 

 

H

—

C

—

O

—

C

—

R

 

 

 

 

 

|

 

 

 

 

 

 

 

 

 

 

 

 

|

 

 

 

 

 

 

 

 

 

 

 

H

 

 

 

 

 

 

 

 

 

 

 

 

H

 

 

 

 

 

 

 

 

 

glycerol

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1,2,3-propanetriol

 

3 organic acids

 

 

a saturated fat

 

Note that to increase the yield of esters, concentrated sulfuric acid is added to decrease the concentration of the water and favoring the forward reaction.

 

Problems

1. What ester is produced when hexanoic acid reacts with 1-butanol?

2. What are the organic acid and the alcohol needed to make pentyl heptanoate?

3. Write the  reaction for the production of butyl butanoate.

4. What is the by product of esterification?

 

Saponification reactions are the reverse of esterification reactions or the hydrolysis of esters (fats) by bases.

Example

 

 

H

 

 

 

O

 

 

 

 

 

 

 

 

 

H

 

 

 

 

 

 

 

O

 

 

 

 

|

 

 

 

| |

 

 

 

 

 

 

 

 

 

|

 

 

 

 

 

 

 

| |

 

 

H

—

C

—

O

—

C

—

R

 

 

 

 

 

H

—

C

—

OH

 

Na

—

O

—

C

—

R

 

 

|

 

 

 

 

 

 

 

 

 

 

 

 

 

|

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

O

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

O

 

 

 

 

 

 

 

| |

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

| |

 

 

H

—

C

—

O

—

C

—

R

+

3 NaOH

-->

H

—

C

—

OH

+

Na

—

O

—

C

—

R

 

 

|

 

 

 

 

 

 

 

 

 

 

 

 

 

|

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

O

 

 

 

a hot base

 

 

 

 

 

 

 

 

 

 

O

 

 

 

 

 

 

 

| |

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

| |

 

 

H

—

C

—

O

—

C

—

R

 

 

 

 

 

H

—

C

—

OH

 

Na

—

O

—

C

—

R

 

 

|

 

 

 

 

 

 

 

 

 

 

 

 

 

|

 

 

 

 

 

 

 

 

 

 

 

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

a molecule of saturated fat

 

 

 

 

 

glycerol

 

a soap

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(salt of an organic acid)

 

Problems

1. Write the structural formula of the soap produced when ethyl propanoate reacts with hot KOH.

2. What ester and hot base are needed to make CH3CH2CH2CH2CH2COOLi if the alcohol produced is CH3CH2CH2CH2OH?

 

Fermentation reactions are the reactions of a sugar, with the help of a catalyst, to yields an alcohol and carbon dioxide. Ethanol is the alcohol present in beers, wines, ect...

Example

 

zymase (from yeast)

 

C6H12O6 (glucose)

------------------->

2 C2H5OH (ethanol) + 2 CO2

 

Combustion reactions are the reactions of a saturated hydrocarbon with excess oxygen to yield carbon dioxide and water.

Example

CH4(g) + 2 O2(g) --> CO2(g) + 2 H2O(g)

2 C4H10(g) + 13 O2(g) --> 8 CO2(g) + 10 H2O(g)

 

Note that burning in a limited supply of oxygen may produce carbon monoxide, CO(g) and carbon C(s) as well.

 

TEST YOUR UNDERSTANDING

1/07

26 Given the balanced equation representing a reaction:    CH3CH2CH3 + Br2 ---> CH3CH2CH2Br + HBr

This organic reaction is best classified as (1) an addition reaction (2) an esterification reaction  (3) a polymerization reaction (4) a substitution reaction

6/07

78 Given the balanced equation for producing bromomethane: Br2 + CH4 ---> CH3Br + HBr     Identify the type of organic reaction shown.

1/06

42 Given the incomplete equation for the combustion of ethane:

What is the formula of the missing product?

46 Given the balanced equation for an organic

reaction:

This reaction is best classified as    (1) addition (2) esterification (3) fermentation (4) substitution

6/06

46 Given the balanced equation with an unknown compound represented by X:

Which compound is represented by X?

Base your answers to questions 61 through 62 on the information below.

Given the balanced equation for an organic reaction between butane and chlorine that takes place at 300.°C and 101.3 kilopascals:

61 Identify the type of organic reaction shown.

62 Draw a structural formula for the organic product.

8/06

Base your answers to questions 61 through 62 on the equation below, which represents an organic compound reacting with bromine.

61 What is the IUPAC name for the organic compound that reacts with Br2?

62 What type of organic reaction is represented by this equation?

63 What is the gram-formula mass of the product in this reaction?

1/05

Base your answers to questions 59 and 60 on the condensed structural formula below.

                                                 CH3CH2CHCH2

59 In the space provided in your answer booklet, draw the structural formula for this compound.

60 The formula below represents a product formed when HCl reacts with  CH3CH2CHCH2  What is an IUPAC name for this product?

            

61 Given the equation: To which class of organic compounds does product X belong?

6/05

Base your answers to questions 59 and 60 on the information below. Given the reaction between 1-butene and chlorine gas:

C4H8 + Cl2 ---> C4H8Cl2

59 Which type of chemical reaction is represented by this equation?

60 Draw the structural formula of the product 1,2-dichlorobutane.

1/04

43 Given the equation: C2H6 + Cl2 ---> C2H5Cl + HCl   This reaction is best described as
        (1) addition involving a saturated hydrocarbon             (2) addition involving an unsaturated hydrocarbon

        (3) substitution involving a saturated hydrocarbon      (4) substitution involving an unsaturated hydrocarbon

Base your answers to questions 68 through 70 on the information below. Many artificial flavorings are prepared using the type of organic reaction shown below.

68 What is the name of this organic reaction?
69 To what class of organic compounds does reactant 2 belong?
70 Draw the structural formula of an isomer of reactant 2.

6/04

24 Given the reaction:

This reaction is an example of  (1) fermentation (3) hydrogenation (2) saponification (4) esterification

63 In the space to the right of the reactants and arrow draw the structural formula for the product of the reaction shown.

 

8/04

Base your answers to questions 73 through 75 on the information below.

Ethene (common name ethylene) is a commercially important organic compound. Millions of tons of ethene are produced by the chemical industry each year. Ethene is used in the manufacture of synthetic fibers for carpeting and clothing, and it is widely used in making polyethylene. Low-density polyethylene can be stretched into a clear, thin film that is used for wrapping food products and consumer goods. High-density polyethylene is molded into bottles for milk and other liquids. Ethene can also be oxidized to produce ethylene glycol, which is used in antifreeze for automobiles. The structural formula for ethylene glycol is:

At standard atmospheric pressure, the boiling point of ethylene glycol is 198°C, compared to ethene that boils at –104°C.

73 Identify the type of organic reaction by which ethene (ethylene) is made into polyethylene.

74 According to the information in the reading passage, state two consumer products manufactured from ethene.

75 Explain, in terms of bonding, why ethene is an unsaturated hydrocarbon.

1/03

Which formula correctly represents the product of an addition reaction between ethene and chlorine?  (1) CH2Cl2    (2) CH3Cl    (3) C2H4Cl2  (4) C3H3Cl

6/03

45. Which type of reaction is represented by the equation below?

Note: n are very large numbers equal to about 2000.

            (1) esterification (2) fermentation (3) saponification (4) polymerization

6/02

The process of joining many small molecules into larger molecules is called   (1) neutralization (2) polymerization  (3) saponification  (4) substitution

8/02

 In which reaction is soap a product?  (1) addition     (2) substitution    (3) saponification    (4) polymerization

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