Basic chemistry

Bases Substances with bitter taste and give a soapy touch are known as bases but many bases have corrosive nature. So bases are defined as "  According to Arrhenius : those substances which give hydroxide or hydroxyl ion (OH - ) in their aqueous solution" are called bases. Properties of Bases The following are the characteristic properties of bases:  1. Taste and Touch  Bases have a bitter taste and their solutions are soapy to touch. 2. Action on indicators . The colours shown by three commonly used indicators in presence of bases are listed below for easy recall.    colours of some common indicators in basic solution  Indicator  colour in basic medium    1. Litmus  Blue    2. Phenolphthalein  Pink    3. Methyl orange  Yellow   3.Conduction of electricity and dissociation of bases  Aqueous solutions (solution in water ) of basesconduct electricity which is due to the forma

properties and classification of acids  We can categorize a substance as an acid or a base according to the properties. Let us learn the characteristics properties of acids. Properties of acids The following are the characteristic properties of acids: 1.Taste :  The sour taste of many unripe fruits , lemon , vinegar and sour milk is caused by the acids present in them. Hence , we can say that acids have a sour taste.                                                                            Acids present in some substances . 2. Action on indicators .  Indicators show different colours in presence of acid and bases . The three commonly used indicator in presence of acids.                                  colour of some indicator in presence of acids .  3. Conduction of electricity and dissociation of acids  When acids are dissolve in water they produce ions which help in conducting the electricity. This process is known as dissociation . More specifically , acids

 INDICATORS   The substances which are neither acidic nor basic and are chemically inert in nature. Touching or tasting of acid or base is very harmful and hence typical indicators are used to recognise them. The substances which change their colours in presence of acid or base are called ‘Indicators’.  you might have seen that the spot of turmeric on cloth becomes red when soap is applied on it. what do you think has happened? Tumeric has acted as an indicator of base present in soap. There are many substances that shows one colour in an acidic medium and another colour in a basic medium. such substances are called acid base indicator.  litums is a natural dye founded in certain lichens. It was the earliest indicator to be used. it shows red colour in acidic medium and blue colour in basic solutions . phenolphthalein and methyl orange are some other indicators. The colour of these indicator in acidic, neutral and basic solutions are given below in the table. Indicato

ACIDS AND BASES     For thousands of years, people have known that vinegar, lemon juice, amla, tamarind and many other food items taste sour. However, only a few hundred years ago it was proposed that these things taste sour because they  contain 'acids'. The term acid comes from Latin term 'accre' which means sour . It was first used in the seventeenth century by robert boyle to label substance as acids and bases according to the following characteristics.   While Robert Boyle was sussessful in characterising acids and bases he could not explain their behaviour on the basis of their chemical structure.This was accomplished by Swedish scientist  Svante Arrhenius in the late nineteenth century. He proposed thaton dissolving in water , manycompounds dissociate and form ions and their properties are mainly the properties of the ions they form. Governed by this, he identified the ions furnished by acids and bases responsible for thier characteristics behaviour a