CHEMISTRY

Hydrocarbons are organic compounds containing hydrogen and carbon only. All hydrocarbons have the general molecular formula of C x H y Examples of hydrocarbons include methane[ CH 4 ], ethene[C 2 H 4 ], ethyl[ C 2 H 2 ], benzene[ C 6 H 6 ], etc  Hydrocarbons are classified into two main groups according to their structure. 1. Aliphatic hydrocarbons  2. Aromatic hydrocarbons                                Sources of hydrocarbons  The natural sources of hydrocarbons are: 1. Natural gas 2. Crude oil (Petroleum) 3. Coal They are known as fossil fuels. •Natural gas is a gaseous fuel •Petroleum is a dark viscous liquid fuel •Coal is a solid fuel                  Crude oil (Petroleum) Crude oil  is a dark and sticky viscous liquid found in the underground. It contains hydrocarbons such as alkanes, alkenes, etc....

Chlorine is the most important element in the halogen family. It does not occur as a free element in nature because it is too reactive. It is usually found in the combined state as chlorides e.g. NaCl. Which is found in the sea and as salt deposits. Atomic mass =35.5  Atomic number = 17  Electronic configuration= 1s 2 2s 2 2p 6 3s 2 3p 5  OR [Ne]3s 2 3p 5           Electronic shell configuration  The nucleus contains 17   protons   and 18 neutrons  There are two stable isotopes of chlorine. They are  37 Cl  and  35 Cl. Chlorine has a naturally occurring radioactive isotope, the cosmogenic isotope,  36 Cl . A Swedish chemist, Carl Wilhelm Scheele, discovered chlorine in 1774. A.  Laboratory preparation of chlorine   The laboratory method for the preparation of chlorine: 1. Using manganese (IV) oxide. Heat a mixture of Manganese(IV) oxide and concentrated HCl. T...

                       Chemical industry  A chemical industry is defined as one that uses chemistry to make chemicals from other chemical raw materials.                Important raw materials  The important raw materials used in the chemical industry include: 1. Petroleum  2. Natural gas  3. Coal  4. Air  5. Seawater  6. Limestone  7. Metallic ore e.g. Iron ore  8. Sulphur  9. Rock salt                Heavy and fine chemicals  Heavy chemicals:  Heavy chemicals are chemicals that are produced in large quantities and used extensively in industries. Examples of heavy chemicals are: 1. Tetraoxosulphate (VI) acid, [H 2 SO 4 ] 2. Hydrochloric acid, [HCl] 3. Trioxonitrate (V) acid, [HNO 3 ] 4. Calciumtrioxocarbonate (IV), [CaCO 3 ] 5. Caustic soda, [NaOH] 6. Slaked lime, [Ca(OH) 2 ] 7....

Chemical formula:  This is the formula that shows the elements in a particular chemical substance and the number of each atom present Types of Chemical Formula There are three basic types of chemical formula:  1.  Empirical formula  2.  Molecular formula  3.  Structural formula  1. Empirical formula: This is the chemical formula that gives the simplest whole number ratio of atoms present in a compound. 2. Molecular formula: This is the  chemical formula that gives the total number of atoms of each element in each molecule of a compound. 3. Structural formula: This is the chemical formula that shows the location of chemical bonds between the atoms of a molecule.       The structural formula of methane The chemical formula of some compounds: 1.   Sodium hydroxide: NaOH  2. Potassium hydroxide: KOH  3. Calcium hydroxide:  Ca(OH)₂ 4. Sodium chloride(Tabl...

A chemical equation  is a symbolic representation of a chemical reaction in which the reactants and products are denoted by their respective chemical formulae. An example of a chemical equation is the reaction between hydrogen and oxygen to form water.              2H 2(g)  + O 2(g)  → 2H 2 O (g)               Reactant             Product  The  reactant side  is the part of the chemical equation to the left of the ‘→’ symbol whereas the  product side  is the part to the right of the arrow symbol. Examples: Balance the following reactions 1. Al + O 2  → Al 2 O 3 2.  N 2  + H 2  → NH 3 Solution:   1. 4 Al + 3 O 2  → 2 Al 2 O 3.  2.  N 2  + 3 H 2  → 2 NH 3.     React and balance the following: 1.  FeCl 3(s)  + NaOH → 2.  FeSO ...

                   OCCURRENCE  Iron occurs naturally as ores. The common iron ores are: 1. Haematite ( Fe 2 O 3 ) 2. Magnetite ( Fe 3 O 4 ) 3. Iron pyrite (Fe S 2 ) 4. Siderite ( Fe CO 3 ) 5. Limonite(  Fe 2 O 3 .H 2 O ) Iron is the second most abundant metal found in the earth's crust after aluminum. It is also present in clay soil, hemoglobin in animals, and chlorophyll in plants.                    EXTRACTION OF IRON 1. The iron ore (Haematite) is first roasted in air to produce Iron (III)oxide , [Fe 2 O 3 ] 2. Iron (III)oxide is then mixed with Coke (Carbon) and limestone (CaCO 3 ) to a very high temperature in the blast furnace  3. In the lower part of the furnace, white-hot coke is oxidized by the oxygen in the hot air to produce carbon (IV) oxide.                   C ( s )  + O 2 ( g )  → CO 2 (...

                          ALLOY An alloy is a substance formed from the combination of two or more metals. Examples of alloys and their components: 1. Brass: Copper and Zinc  2. Bronze: Copper and Tin  3. Steel: Iron and Carbon  4. Stainless steel: Iron, chromium and Nickel  5. Duralumin: Aluminium, copper, magnesium and manganese  6. Solder: Lead and Tin                         Uses of alloy  1. Brass: for making nuts, bolts, rods, musical instruments, etc  2. Bronze:  for making medals, coins, sculptures, etc 3. Steel:  for making household fittings such as taps, doors, hinges, and door handles 4. Stainless steel:  for making cutlery, tools, surgical equipment, etc 5. Duralumin:  Construction of aircraft, ships, cars, and machinery 6. Solder:  for welding and plumbing   ...

Molar mass is the mass per unit mole of a given chemical substance. The S.I.unit of molar mass is g/mol  Examples : Calculate the molar mass of the following: 1. Water (H 2 O) 2. Table salt (NaCl) 3. Calcium oxide (CaO) 4. Calcium carbonate (CaCO 3 )    [H=1, O=16, Na=23, Cl=35.5, C=12, Ca=40] Solution:  1. H 2 O= 2(1) + 16              = 18g/mol  2. NaCl= 23 +35.5               =58.5g/mol  3. CaO= 40+16              =56g /mol  4. CaCO 3  = 40+12+3(16)                    =52+48                    =100g/mol                    NUMBER OF ATOMS Calculate the number of atoms in each of the following: 1. H 2 O 2. Three moles of  H 2 O 3. NaOH  4. Two moles of NaOH...

             SEPARATION TECHNIQUES  Separation techniques are physical methods used for the separation of the constituents of a mixture. A mixture contains two or more substances that are physically combined. Examples of separation techniques are:  1. Sieving 2. Filtration  3. Sublimation  4. Decantation  5. Separating funnel  6. Evaporation  7. Centrifugation  8. Distillation  9. Fractional distillation  10. Chromatography  11. Crystallization  12. Fractional crystallization  13. Magnetic separation    SIEVING This is used to separate solid particles of different sizes. Particles smaller than the size of the sieve (mesh) pass through leaving behind particles of larger sizes. It is used in gold and diamond mines and garri industries.                             Sieving FILTRATION  Th...

                              Rusting  Rusting  is also known as corrosion of iron. It is defined as the  interaction of Iron with air and water to produce rust When iron is exposed to air and moisture, its surface gradually corrodes and converts into a brown mass. This brown mass is called rust and this phenomenon is known as rusting.          Conditions for rusting of iron  1. Presence of water  2. Presence of air (Oxygen) The iron reacts with water and oxygen to form hydrated iron(III) oxide, [ Fe₂O₃]  which we see as rust. The corrosion of metals results from the combined action of atmospheric oxygen and water. The most important example of metallic corrosion is that of iron.              Prevention of Rusting There are several ways of preventing the rusting of iron: 1. Painting: Applying paint on iron 2. Greasing: Appl...

Chemical formula: This is the formula that shows the elements in a particular chemical substance and the number of each atom present. The chemical formula of some compounds: 1. Carbon (II) oxide: CO 2. Carbon (IV) oxide: CO₂ 3.  Sulphur (II) oxide:  SO 4. Sulphur (IV) oxide:  SO 2 5. Ammonia: NH 3 6. Ammonium: NH 4 7. Methane: CH 4 8. Quicklime: CaO 9. Water: H 2 O 10. Hydrochloric acid: HCl

Petrochemicals are substances that are manufactured from the by-products of petroleum.            Petrochemical products  Products made from petrochemicals include the following items: 1. Plastics  2. Fertilizers  3. Detergents  4. Pesticides  5. Drugs  6. Cosmetics  7. Food additives  8. Paints  9. Textile materials  10. Synthetic rubber etc             The importance of crude oil and petrochemicals: 1.  Provision of employment  2. Sources of revenue for individuals and country  3. Sources of energy  4. Provision of raw materials for the industry                Petrochemical products

                  Crude oil (Petroleum) Crude oil is a dark and sticky viscous liquid found in underground. It contains hydrocarbons such as alkanes, alkenes, etc. Natural gas is found together with crude oil. Natural gas consists mainly of methane.  Crude oil is measured in  barrels.   1 barrel = 159 litres       Fractional distillation of crude oil  Fractional distillation is the process used to separate crude oil into its fractions.                   Fractions of crude oil  The fractions of crude oil are: 1.   Petroleum gas  2. Petrol  3. Kerosene  4. Diesel  5. Lubricating oil  6. Bitumen                  Uses of crude oil  1.  Petroleum gas: Used as domestic fuel 2. Petrol: Used as fuel in motor vehicles 3. Kerosene: Used as fuel for heating and li...

                             Matter  Matter is anything that has mass and occupies space.                       States of Matter  Matter exists in three states: 1. Solid state  2. Liquid state  3. Gaseous state  The difference between the three states of matter is the degree of movement of their particles. The processes involved during changes in the States of Matter                                                                  Assignment .                      Identify the letters