Question

chemical properties of base with definition
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Answer 1

Answer:

Chemical Properties of Bases

In the chemical properties of acids and bases, we now focus on bases. Bases change the colour of litmus from red to blue. They are bitter in taste. Bases lose their basicity when mixed with acids. Bases react with acids to form salt and water.

Answer 2

Answer: Chemical properties of bases:

1. Bases react with acids to form salts and water.
2. Bases react with non metal-oxides to produce salt and water.
3. Bases turn red litmus paper blue.
4. Bases conduct electricity in solution.
5. Changes colour of phenolphthalin in purple.

Explanation:

Definition of bases varies in many senses. There were many scientists who discovered there own way of defining bases and acids as well. But only few were accepted. Some of the theories were;

Arrhenius Theory of acids and bases:

According to Arrhenius, bases are those compound that furnish -OH ions when dissolved in water.

Like- NaOH(when dissolved in water) ---> Na+ + OH-

Lowry-Bronsted Theory of Acids and Bases:

According to J.N. Bronsted and J.M. Lowry, bases are those substances that accept protons from any proton donor(i.e, Lowry-Bornsted acids).

Like- NH3 + H+ ---> NH4+

here, NH3 is accepting a proton(which is a hydrogen with only proton). Hence, it is a base.

Lewis Theory of Acids and Bases:

According to G.N. Lewis, base is a substance which can act as electron pair donor.

Like- NH3 + H+ ---> NH4+

here, NH3 is donating electron to H+, hence NH3 is a base.

Definition of Bases in terms of changes in indicators :

Litmus paper :

Bases are those compounds that changes red litmus paper into blue color.

Phenolphthalein :

Bases are those compounds that changes phenolphthalin (which is colourless when nothing is dissolved) in purple( or pink) colour.

Methyl Orange :

Bases are those compounds that change methyl orange into yellow colour from its initial orange colour (neutral colour).

Universal Indicator :

Bases are those compounds that change the colour of universal indicator from green(not green itself, because it will be neutral) to violet.

That's all.