CHEMISTRY

A mixture is a substance that contains two or more constituents that can easily be separated by physical methods. Examples of mixtures are  Air, Soil, Urine, Palm wine, Crude oil, Sea water, Blood, Alloy, etc               Types of Mixtures The two types of mixtures are: I. Homogeneous Mixtures II. Heterogeneous Mixtures         A. Homogeneous Mixtures Homogeneous Mixtures have a uniform composition throughout. The different components cannot be easily seen. They are also called solutions. Examples: Sugar dissolved in water Air Alcohol in water          B. Heterogeneous Mixtures Heterogeneous Mixtures have a non-uniform composition. The components can be easily seen and separated. Examples: Sand and water Oil and water Salt and pepper             Properties of Mixtures 1. Components are not chemically combined. 2. Components can be separated by physical methods. 3. Composit...

A compound is a substance that contains two or more elements that are chemically combined in a fixed ratio.  Examples of compounds are  Water (H2O) Sand (SiO2) Limestone (CaCO3) Common salt (NaCl) Ethanol (C2H5OH) Caustic soda (NaOH) Washing soda (Na2CO3.H2O) etc           Formation of Compounds Compounds are formed through chemical reactions between elements. The reaction involves chemical bonds either Ionic (electrovalent) bond or covalent bond. Example: Hydrogen burns in oxygen to form water. 2H₂ + O₂ → 2H₂O             Classification of compounds Chemical compounds can be classified in two major ways: (I) Classification based on how atoms bond (II) Classification based on their composition  (1)  Classification based on how atoms bond I. Ionic (Electrovalent) compounds: Ionic compounds are formed when atoms transfer electrons, creating charged particles called ions. It usually happens between a met...

Temperature is a measure of the degree of hotness or coldness of a body. The instrument for measuring the temperature of a body is THERMOMETER. Temperature can be measured in degree Celsius (oC), Kelvin (K) or Farenheit (F) The normal body temperature is 37oC.                 Temperature scale

BOYLE'S LAW states that the volume of a given mass of a gas is inversely proportional to the pressure provided the temperature remains constant. Proportional Relationship: V ∝ 1/P (V is inversely proportional to P) V = k/P P V = k where: P = Pressure, V = Volume k = a constant value for a given sample of gas at a constant temperature. P₁V₁ = k and P₂V₂ = k, we can set them equal to each other. This gives us the most practical form of Boyle's Law: P₁V₁ = P₂V₂ Where: P₁ and V₁ are the initial pressure and volume. P₂ and V₂ are the final pressure and volume.               Graphs of Boyle's law      Simple calculations on Boyle's law 1. When the pressure on a gas increases at constant temperature, the volume will (a) increase (b) decrease (c) remain constant (d) first increase then decrease 2. The volume of a given mass of a gas at 10oC and 600mmHg is 140cm3. What will be the volume of the gas at 10oC, if the pressure...

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. Types of Separation techniques  The types of separation techniques are:  1. Sieving 2. Magnetic Separation  3. Sublimation  4. Decantation  5. Filtration  6. Centrifugation  7. Evaporation  8. Crystallization  9. Fractional crystallization  10. Precipitation  11. Distillation  12. Fractional distillation  13. Separating funnel method  14. Chromatography                           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.               ...

An element is a pure substance composed of only one type of atom and cannot be broken down into simpler substance by ordinary chemical means . There are a total of 118 elements in the modern periodic table.                   Types of elements  Elements can be grouped into three: 1. Metals 2. Metalloids  3. Non-metals  The first twenty elements of the periodic table and their symbols are: 1. Hydrogen (H) 2. Helium (He) 3. Lithium (Lithium) 4. Beryllium (Be) 5. Boron (B) 6. Carbon (C) 7. Nitrogen (N) 8. Oxygen (O) 9. Flourine (F) 10. Neon (Ne) 11. Sodium (Na) 12. Magnesium (Mg) 13. Aluminium (Al) 14. Silicon (Si) 15. Phosphorus (P) 16. Sulphur (S) 17. Chlorine (Cl) 18. Argon (Ar) 19. Potassium (K) 20. Calcium (Ca) Some other elements in the periodic table include;  Iron(Fe), Copper (Cu), Zinc (Zn), Tin (Sn), Lead (Pb), Manganese (Mn), Nickel (Ni), Cobalt (Co), Vanadium (V) and Chromium (Cr) etc     ...

SCIENTIFIC METHOD is also known as scientific discovery. It is defined as a way of studying problems objectively to establish facts through testing and experimentation. The scientific methods include: 1. Observation  2. Hypothesis  3. Experiment  4. Theory  5. Scientific law or principle.                     Observation Observation involves the use of senses to perceive what is happening in the environment.                     Hypothesis Hypothesis means to give a reasonable explanation for an observation.                     Experiment The experiment is a scientific procedure undertaken to demonstrate a known fact.                     Theory Theory is a set of principles on which the practice of an identity is based.            ...

REDOX REACTION is a reaction involving both oxidation and reduction occuring at the same time. Most chemical reactions are redox reactions except neutralization reactions and precipitation reactions. Redox reactions can be explained in four different ways: 1. Redox in terms of electron transfer 2. Redox in terms of change in oxidation number (O.N.) 3. Redox in terms of addition or removal of oxygen and hydrogen  4. Redox in terms of addition or removal of electronegative and electropositive elements        Redox in terms of electron transfer   (I) Oxidation is the process of electron loss (II) Reduction is the process of electron gain (a)   H₂(g) + Cu²⁺ (aq) → Cu(s) + 2H⁺(aq) O.N.:  0             +2                0             +1  (I) Cu²⁺ (aq) is undergoing reduction (is reduced). Hence Cu²⁺ (aq) is an oxidizing age...

Matter is anything that has mass and occupies space. Examples of matter include; Air, water, rocks, plants, animals, and even people.  Matter is made up of one or more of the following: atoms, molecules, and ions.                  STATES OF MATTER   Matter exists in three different major states which are  1. Solid state  2. Liquid state   3. Gaseous state                                 CHANGES IN MATTER  Changes in matter can be categorized into two namely, 1. Physical change  2. Chemical change                         Physical changes  A physical change is a change that can be easily reversed and no new substances are formed. Examples of physical changes are  1. Melting of solid to liquid  2. Freezing of liquid to solid...

CHEMISTRY  is a branch of pure science that deals with the study of the nature, structure, composition, properties, and uses of matter. The scientist who studies chemistry is called a CHEMIST             BRANCHES OF CHEMISTRY  The three main branches of chemistry are  1. Physical chemistry  2. Organic chemistry  3. Inorganic chemistry  Physical chemistry  deals with the physical aspects of chemistry such as heat, electricity, etc. Organic chemistry  deals with the study of carbon and its compounds Inorganic chemistry  deals with the study of elements, their properties, and uses REASONS FOR STUDYING CHEMISTRY The reasons for studying chemistry are:  1. To acquire knowledge about matter 2. To give training in the scientific method 3. To meet basic needs such as food, clothing, shelter, health, etc 4. To provide solutions to problems 5. To explore new things which are unknown to mankind....