Tuesday , December 6 2016
Revision Notes

IGCSE / O Level Chemistry Revision Notes

Acids

ACIDS

Acids: An acid is a substance, which forms H+ ions. When dissolved in water, they can conduct electricity. E.g. HClH+     +    Cl – H+ ion is proton Acids are called proton donors as provide H+   ions   General Properties: Turns Blue Litmus Paper Red. Acid reacts with Metals to produce ...

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Bases

Bases

Bases: Bases are metal oxides and metal Hydroxides. A base is a a substance, that can accept H+ ions and therefore are proton acceptor. Example: Copper(II) Oxide (CuO) Iron(III) Oxide (Fe2O3) Copper (II) Hydroxide (Cu(OH)2) Iron (III) Hydroxide (Fe2O3) It reacts with an acid to give salt and water only. ...

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Salts

SALTS

Salts: Salts are Ionic Compounds. A salt is formed when a metallic ion or an ammonium ion (NH4+) replaces one or more Hydrogen Ions of an acid. A Salt contains a positive metal ion and a negative non – metal ion. Example: Zn(OH)2   + H2SO4ZnSO4    2H2O   Water of Crystalization: ...

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IGCSE / O Level Economics Revision Notes

Basic Economic Problem

Basic Economic Problem

Basic Economic Problem: The basic economic problem is that there are finite resources and unlimited wants; in other words there are unlimited human wants, and resources which are used to make those goods are limited. The basic economic problem arises when wants are unlimited and resources are scarce.

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Production Possibility Curve

Production-Possibility-Curve

Production Possibility Curve: The following is a curve representing all possible combinations of two goods that can be produced by an economy where all of its resources are fully and efficiently employed. Point X: The economy can exist at this point but it is being inefficient. Point X Is considered ...

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Allocation Of Resources In Economic Systems

Allocation-of-resources-in-economic-systems-2

Resource Allocation Answers Three Questions: What to produce? How to produce? For whom to produce? Economic Systems: How an economy decides, how to allocate its resources is its economic system. There are three kinds of economic systems: Free Market Economy Planned Economy Mixed Economic System   Free Market Economy: It is ...

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IGCSE / O Level Mathematics Revision Notes

Number

Numbers-3

Natural Numbers: The natural numbers include whole numbers except 0. E.g. 1,2,3,4,5,6… Integers: Positive natural ...

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Matrices

Matrices-3

In Mathematics, matrices are arrays of numbers arranged in rows and columns. Types of Matrices: ...

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IGCSE / O Level Physics Revision Notes

IGCSE / O Level Islamaiyat Revision Notes