PROPERTIES OF HYDROGEN GAS
(a) Physical properties Hydrogen is a neutral, colourless and odourless gas. When mixed with air it has a characteristic pungent choking smell It is insoluble in water thus can be… Read More »PROPERTIES OF HYDROGEN GAS
Chemistry
HYDROGEN
Occurrence Hydrogen does not occur free in nature. It occurs as Water and in Petroleum. School laboratory Preparation Procedure Put Zinc granules in a round/flat/conical flask. Add dilute sulphuric(VI) /Hydrochloric… Read More »HYDROGEN
REACTION OF METALS WITH WATER
REACTION OF METALS WITH WATER The higher the metal in the reactivity series the more reactive the metal with water. The following experiments show the reaction of metals with cold… Read More »REACTION OF METALS WITH WATER
WATER POLLUTION
WATER POLLUTION Water pollution take place when undesirable substances are added into the water. Sources of water pollution include: (i) Industrial chemicals being disposed into water bodies like rivers, lakes… Read More »WATER POLLUTION
WATER
WATER Pure water is a colourless, odourless, tasteless, neutral liquid. Pure water does not exist in nature but naturally in varying degree of purity. The main sources of water include… Read More »WATER
REACTIVITY SERIES OF METALS/ELEMENTS
REACTIVITY SERIES OF METALS/ELEMENTS Metals compete for combined Oxygen. A metal/element with higher affinity for oxygen removes Oxygen from a metal lower in the reactivity series/less affinity for Oxygen. When… Read More »REACTIVITY SERIES OF METALS/ELEMENTS
REACTION OF NON-METALS WITH OXYGEN/AIR
The following experiments show the reaction of non-metals with Oxygen and air. Burning Carbon Procedure (a) Using a pair of tongs hold a dry piece of charcoal on a Bunsen… Read More »REACTION OF NON-METALS WITH OXYGEN/AIR
USES OF OXYGEN
Oxygen is put in cylinders for use where natural supply is not sufficiently enough. This is mainly in: (i) Mountain climbing/Mountaineering-at high altitudes, the concentration of air/oxygen is low. Mountain… Read More »USES OF OXYGEN
REACTION OF METALS WITH OXYGEN/AIR
The following experiments show the reaction of metals with Oxygen and air. Burning Magnesium Procedure (a) Cut a 2cm length piece of magnesium ribbon. Using a pair of tongs introduce… Read More »REACTION OF METALS WITH OXYGEN/AIR
OXYGEN
OXYGEN a) Occurrence. Fifty 50% of the earth’s crust consist of Oxygen combined with other elements e.g. oxides of metals About 70% of the earth is water made up of… Read More »OXYGEN
THE ATMOSPHERE
THE ATMOSPHERE The atmosphere is made up of air. Air is a mixture of colourless, odourless gases which is felt as wind (air in motion). All living things breathe in… Read More »THE ATMOSPHERE
INTRODUCTION TO ACIDS, BASES AND INDICATORS
. In a school laboratory: (i) An acid may be defined as a substance that turns litmus red. (ii) A base may be defined as a substance that turns litmus… Read More »INTRODUCTION TO ACIDS, BASES AND INDICATORS
PROPERTIES OF ACIDS
(A) PHYSICAL PROPERTIES OF ACIDS Acids have a characteristic sour taste Most acids are colourless liquids Mineral acids are odourless. Organic acids have characteristic smell All acids have pH less… Read More »PROPERTIES OF ACIDS
PHYSICAL/TEMPORARY AND CHEMICAL CHANGES
A physical/temporary change is one which no new substance is formed and is reversible back to original. A chemical/permanent change is one which a new substance is formed and is… Read More »PHYSICAL/TEMPORARY AND CHEMICAL CHANGES
METHODS OF SEPARATING MIXTURES
METHODS OF SEPARATING MIXTURES Mixtures can be separated from applying the following methods: (A) DECANTATION Sediments can be separated from a liquid by pouring out the liquid. This process is… Read More »METHODS OF SEPARATING MIXTURES
CLASSIFICATION OF SUBSTANCES
CLASSIFICATION OF SUBSTANCES Substances are either pure or impure. A pure substance is one which contains only one substance. An impure substance is one which contains two or more substances.… Read More »CLASSIFICATION OF SUBSTANCES
THE ROLE OF CHEMISTRY IN SOCIETY
(a) Chemistry is used in the following: (i) Washing/cleaning with soap: Washing/cleaning is a chemical process that involves interaction of water, soap and dirt so as to remove the dirt… Read More »THE ROLE OF CHEMISTRY IN SOCIETY
CHEMISTRY LABORATORY AND APPARATUS
CHEMISTRY LABORATORY AND APPARATUS Chemistry is studied mainly in a science room called a school chemistry laboratory. The room is better ventilated than normal classroom. It has electricity, gas and… Read More »CHEMISTRY LABORATORY AND APPARATUS
WATER ON EARTH
WATER ON EARTH Water is an important item in our universe. We need water for transport (lakes and oceans), Generation of power, (hydroelectricity), drinking industrial processes, manufacturing and cooling among… Read More »WATER ON EARTH
INTRODUCTION TO CHEMISTRY
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.… Read More »INTRODUCTION TO CHEMISTRY