Class 10 - Chemistry - Chapter - Acids and Bases - Keys Points To Remember (#class10Chemistry)(#cbsenotes)(#eduvictors)

 Acids and Bases 

Class 10 - Chemistry 

(Important Points To Remember)

⑴ Acids are the substances which taste sour, change blue litmus red, are corrosive to metals and furnish H⁺ ions in their aqueous solutions.

⑵ Bases are the substances which taste bitter, change red litmus blue, feel slippery and furnish OH⁻ ions in their aqueous solutions.

⑶ Acid-base indicators are dyes or mixtures of dyes which are used to indicate the presence of acids and bases.

⑷ Indicators are the substances that show one colour in an acidic medium and another colour in a basic medium. Litmus, phenolphthalein and methyl orange are commonly used indicators. Onion, Vanilla extract and Clove oil are olfactory indicators.



⑸ Acids are presents in many unripe fruits, vinegar, lemon, sour milk etc., while bases are present in lime water, window pane cleaners, many drain cleaners etc.

⑹ When an acid reacts with a metal, hydrogen gas is evolved and a corresponding salt is formed.

⑺ When a base reacts with a metal, along with the evolution of hydrogen gas a salt is formed which has a negative ion composed of the metal and oxygen.

⑻  Living beings carry out their metabolic activities within an optimal pH range.

⑼ Aqueous solutions of acids and bases both conduct electricity as they dissociate on dissolving in water and liberate cations and anions which help in conducting electricity.

⑽ Strong acids and bases dissociate completely in water.

⑾ Weak acids and bases dissociate  partially in water.

⑿ Acids and bases react with each other to produce salt and water. Such reactions are called neutralization reactions.


⒀ Mixing concentrated acids or bases with water is a highly exothermic process.

⒁ Water itself undergoes dissociation and furnishes H⁺ and OH– ions in equal numbers. This is called self dissociation of water.


⒂ In pure water [H⁺] = [OH⁻]. It is also true in any neutral aqueous solution. In terms of pH, pH = pOH = 7 in water and any neutral solution.

⒃ In acidic solution [H⁺] > [OH⁻] and pH < pOH. Also pH < 7 at 25°C.

⒄ In basic solutions [H⁺] < [OH⁻] and pH > pOH. Also pH > 7 at 25°C.

⒅ If pH of rain water falls below 5.6, it is called acid rain and is quite harmful.

☛See Also:

Ch2 - Acids, Bases and Salts (MCQs, NCERT Solution, Q & A)
Ch2 - Acids, Bases and Salts (MCQs)
Ch2 - Acids, Bases and Salts (Worksheet)
Ch 2 - Acids, Bases and Salts (Very Short Q A)
Ch2 - Acids, Bases and Salts - Indicators (Q & A)