Carbon compound

 

1. Carbon compound are divided into two groups , organic and inorganic compound
2. Organic compound are carbon compounds that a derived or obtained from living or once living things
3. Hydrocarbons are organic compounds containing hydrogen and carbon atoms only. Non-hydrocarbon contains other elements such as nitrogen and oxygen besides hydrogen and carbon.

 

Alkanes

 

1. Alkanes are saturated hydrocarbon with general formula C_nH_2n+2, where n= 1,2,3,….
2. The name of alkanes end with ‘-ane’
3. The physical properties of alkanes

a)     The first four members if alkanes exist as gases at room temperature. The other gases at room temperature. The other alkanes exist as volatile liquids or solids

b)     Low melting and boiling points

c)     Lower density than water

d)     Soluble in organic solvent, insoluble in water

4. the two important chemical reaction of alkanes are combustion and substitution

 

Alkenes

 

1. Alkenes are unsaturated hydrocarbon with the general formula C_nH_2n, where n = 2,3,4,…
2. The name of alkenes end with ‘-ene’
3. The physical properties of alkenes:

a)     The first three members of alkenes exist as gases at room temperature. The other gases at room temperature. The other alkenes exist as volatile liquid or solid.

b)     Low melting and boiling points

c)     Lower density than water

d)     Soluble in organic solvents, insoluble in water.

4. The chemical reaction of alkenes include combustion, addition and polymerization
5. Both alkanes and alkenes have similar phyrocal properties but different chemical properties
6. A homologous series is a family or organic compound with each member of the family differing from the previous member by having one more groups of atoms –CH₂-

 

Isomerism

 

1. Isomers are different compound that have the same molecular formula but different structural formula.

 

Alcohols

 

1. Alcohols are a homologous series that contains hydroxyl as the functional groups. The general formula of alcohol is CnH_2n+1OH where n=1,2,3,….
2. The name of alcohol end with ‘ol’
3. Two ways to manufacture ethanol are catalytic addition of steam to ethane and fermentation of sugar or starch with yeast.
4. The physical properties of alcohols:
5. The chemical reaction of alcohol include combustion, oxidation, dehydration and esterification

 

Carboxylic Acids

 

1. Carboxylic acids are a homologous series that contain the carboxyl groups as the functional group. The general formula is C_nH_2n+1COOH where n=0,1,2
2. The name of carboxylic acid end with ‘-oic acid’
3. Ethanoic acid is prepared through the oxidation of ethanol in an excess of acidified potassium dichromate(VI) with concentrated sulphuric acid as the catalyst.
4. The physical properties of ethanoic acids
1. Exist as colourless liquid at room temperature
2. Characteristic smell of vinegar
3. Taste sour
4. Low melting and boiling points
5. Soluble in water
5. Carboxylic acids act as acid in aqueous solution, react with metal, metallic carbonate and bases. Carboxylic acid reacts with alcohol to produce ester and water.

 

Ester

 

1. Esters are a homologous series that contains the carboxylate group. The general formula is C_nH_2n+1 COOC_mH_2m+1
2. the name if esters end with ‘-oate’
3. the physical properties of esters:
1. Exist as colouless liquid at room temperature
2. Low density
3. Insoluble in water
4. Characteristic sweet and fruity smell

 

 

 

11.8 Fats

 

 

1. Fats and oils are ester that are produced from the reaction between fatty acids and glycerol
2. they can be classified into saturated fats and unsaturated fats
3. unsaturated fats can be converted to saturated fats through hydrogenation

 

11.9 Natural Rubber

 

1. Natural rubber is a polymer that is made up of monomer called isoprene , C₅H₈
2. Latex is a milk-like liquid that flows out from a rubber three when it is tapped
3. The presence of an acid coagulates latex. Presence of an alkali such as ammonia solution helps latex as a suspension.
4. Vulcanisation  is the process of treating natural rubber with sulphur to form vulcanised rubber

 

EXERCISE

 

1. Ethanol is manufactured by the reaction between ethane and steam. Figure shows the reaction between ethane and steam

 H   H                                H  H

 |      |                                  |    |

C=C  + H₂O    à          H-C-C-H

 |     |                                   |    |

 H   H                               H  OH

Ethene                             Ethanol

 

1. Describe the reaction between ethane and steam
2. Ethanol can be prepared by fermentation. Explain briefly an activity to carry fermentation in the laboratory
3. A hydrocarbon contain 85.71% by mass of carbon

                                                              i.      Calculate and determine the empirical formula of the hydrocarbon ( Relative atomic mass: H,1;C,12)

                                                             ii.      Calculate the molecular formula of the hydrocarbon if its relative molecular mass is 28.

                                                           iii.      Give the name and structural formula of the hydrocarbon.

2. Table shows the observation for the combustion of hexane, C₆H₁₄ and hex-1-ene C₆H₁₂

 

 

1. Explain why there is a different in these observation ( Relative atomic mass: H, 1; C,12)
2. Describe an experiment to show the combustion of hexane and hex-1-ene
3.  

                                                              i.      What is vulcanization

                                                             ii.      State three different in physical properties between unvulcanised rubber and vulcanised rubber

                                                           iii.      Explain the structural change that occur when unvulcanised rubber is converted to vulcanised rubber

 

3. The structural formula of an ester is shown figure

                                                      H  H H     H H      

|    |   |       |   |

H-C-C-C-O-C-C-H

|    |            |  |

H   H        H  H

1. Name the ester
2. State three uses of this ester
3. Explain briefly an experiment to produce this ester in the laboratory
4. The combustion of butanol will produce carbon dioxide and water

                                                              i.      Write a balanced equation for this reaction

                                                             ii.      Calculate the volume of carbon dioxide produced in 9.25 g of butanol burnt completely in excess oxygen. ( Relative atomic mass: H,1;C,12;O,16; Molar volume : 24 dm³ mol^-1)

4.  
1. Describe an experiment to compare the elasticity of vulcanised and unvulcanised rubber in the laboratory.
2.  

 

 

                                                              i.      Explain the above statement by using a suitable example

                                                             ii.      Suggest a method to prevent coagulation of latex. Explain how coagulation of latex is prevented.