Percentage of Oxygen in Air We have read that Air consists mainly of molecules of oxygen and nitrogen with important yet trace amounts of other gases. We know that the combustion of organic material requires oxygen. The idea here is to capture a quantity of air in a measured and isolated volume and then use […]
Alkali is pronounced like alcohol, with ‘lie’ at the end instead of ‘hol’. An alkali is any substance which produces OH– ions in water. OH– ions are called hydroxide ions. If there are excess of (OH)– ions when a compound is dissolved in water, the solution is called a base or an alkaline solution. A base
WHAT IS ACIDS, BASES AND INDICATORS? All the elements in nature fall into three classes: metals, non-metals and gases. Non-metals are also sometimes called metalloids. The compounds formed by combination of the elements can also be classified as organic and inorganic compounds. Organic compounds are formed from a combination of carbon and hydrogen; they are
EVAPORATION AND BOILING (LIQUID TO GAS) On heating particles gain kinetic energy and move faster. In evaporation and boiling the highest kinetic energy molecules can ‘escape’ from the attractive forces of the other liquid particles. The particles lose any order and become completely free to form a gas or vapour. Energy is needed to overcome
Chemists are the people who transform the everyday materials around us into amazing things. Some chemists work on cures for cancer while others monitor the ozone protecting us from the sun. Still others discover new materials to make our homes warmer in the winter, or new textiles to be used in the latest fashions. The
INTRODUCTION TO CHEMISTRY Chemistry is a branch of Science. Science is basically the study of living and non-living things. The branch of science that study living things is called Biology. The branch of science that study non-living things is called Physical Science. Physical Science is made up of: (i) Physics– the study of matter in
CHEMISTRY SCHEME OF WORK FOR SS 3 CHEMISTRY SS 3- FIRST TERM 1. Petroleum or Crude Oil 2. Metals and their Compounds 3. Iron 4. Quantitative and Qualitative Analysis 5. Ethical, Legal and Social Issues CHEMISTRY SS 3- SECOND TERM 1. Fats and Oil 2. Soap and Detergents 3. Giant Molecules (Sugars, Starch) 4.
CHEMISTRY SS 2- FIRST TERM 1. Periodic Table 2. Chemical Reactions 3. Mass, Volume Relationships 4. Acid-Base Reactions 5. Water. CHEMISTRY SS 2- SECOND TERM 1. Air 2. Hydrogen 3. Oxygen 4. Halogens 5. Nitrogen 6. Sulphur CHEMISTRY SS 2- THIRD TERM 1. Oxidation-Reduction (Redox) Reactions 2. Ionic Theory 3. Electrolysis 4. Hydrocarbons 5. Alkanols
CHEMISTRY SS 1- FIRST TERM 1. Introduction to Chemistry 2. Particulate Nature of Matter 3. Symbols, Formulae and Equations 4. Chemical Combination 5. Gas Laws CHEMISTRY SS 1- SECOND TERM 1. Gas Laws (Cont’d) 2. Standard Separation Techniques for Mixtures 3. Acids, Bases and Salts 4. Water. CHEMISTRY SS 1- THIRD TERM 1. Carbon and
OXYGEN (O2) PROPERTIES AND USES Oxygen (O2) is an active, life-sustaining component of the atmosphere; making up 20% by volume of the air we breathe. It is colorless, odorless and tasteless. Oxygen is the most widely occurring element on earth. Because it forms compounds with virtually all chemical elements except the noble gases, most oxygen
Corrosion The eating up of metals by the action of air and moisture on their surface is called corrosion. The corrosion of iron is called rusting. While other metals are said to ‘corrode’, iron metal is said to ‘rust’. Rusting of Iron When an iron object is left in damp air (or water) for a
WATER AND HYDROGEN Hydrogen is the simplest element. It is the first element in the periodic table, and it is placed in Group I of the periodic table. Hydrogen Occurrence Hydrogen is the lightest element and the most abundant element in the universe. Hydrogen occurs naturally as a mixture of the three isotopes: Protium,
INDICATORS Red cabbage juice solution works well instead of universal indicator solution. Making Cabbage Indicator Acid base indicators are chemicals that change colour in the presence of different pH levels. These are usually larger organic molecules. Some, like that in purple cabbage, are natural. You will be making an acid base indicator from purple
COMPOUNDS AND FORMULA A compound is a pure substance formed by chemically combining at least two different elements. Compounds are two or more different elements combined. Their atoms have been joined or bonded together. Compounds can be represented by a FORMULA. There must be at least two different types of atom (elements) in a
SEPARATION OF MIXTURES Sometimes we need pure substances as opposed to impure ones. You can imagine a mixture of sand and table salt and imagine how much use you would have for it. or imagine the manufacture of drugs and medicines. Purity is highly essential here as it is crucial to our well-being and health.