CBSE Class 10 Science
Revision Notes
CHAPTER – 2
ACIDS, BASES AND SALTS
Acids Bases
Sour in taste
Bitter in taste
Derived from Greek word' ACIDUS'
Changes blue litmus into red Changes red litmus into blue
e.g. Hydrochloric acid HCl e.g. Sodium hydroxide NaOH
Sulphuric acid Potassium hydroxide KOH
Nitric acid Calcium hydroxide
Acetic acid Ammonium hydroxide
Some naturally occurring acids
Vinegar Acetic Acid
Orange Citric Acid
Lemon Citric Acid
Tamarind Tartaric Acid
Tomato Oxalic Acid
Sour milk (Curd) Lactic Acid
Ant and Nettle sting Methanoic Ac
Acid – Base Indicator:Substances which indicate the presence of an acid or base in a
solution.
Litmus solution – It is a natural indicator. It is a purple dye extracted from Lichens.
Other examples are Red Cabbage and coloured petals of Petunia and turmeric.
Olfactory indicators : Show odour changes in acidic or basic media. E.g. onion and
Material downloaded from www.vidyakul.com.
, clove .
Acid – Base Indicators
S.No. Name of the Indicator Colour Change With Acid Colour Change with Base
A. Blue litmus solution To red No change
B. Red litmus solution No change To blue
C. Turmeric No change To red
D. Methyl orange To red To yellow
E. Phenolphthalein (colourless) No change To pink
Dilute Acid : A dilute acid contains a small amount of acid (lower concentration of
hydronium ions)and a large amount of water.
Concentrated Acid :A concentrated acid contains a large amount of acid (higher
concentration of hydronium ions)and a small amount of water.
Chemical Properties of Acids and Bases
1. Reaction with metal
Pop test : When a burning candle is brought near a test tube containing hydrogen gas
it burns with a ‘Pop’ sound. This test is conducted for examining the presence of
hydrogen gas.
Base + Metal Salt + Hydrogen
Material downloaded from www.vidyakul.com.
Revision Notes
CHAPTER – 2
ACIDS, BASES AND SALTS
Acids Bases
Sour in taste
Bitter in taste
Derived from Greek word' ACIDUS'
Changes blue litmus into red Changes red litmus into blue
e.g. Hydrochloric acid HCl e.g. Sodium hydroxide NaOH
Sulphuric acid Potassium hydroxide KOH
Nitric acid Calcium hydroxide
Acetic acid Ammonium hydroxide
Some naturally occurring acids
Vinegar Acetic Acid
Orange Citric Acid
Lemon Citric Acid
Tamarind Tartaric Acid
Tomato Oxalic Acid
Sour milk (Curd) Lactic Acid
Ant and Nettle sting Methanoic Ac
Acid – Base Indicator:Substances which indicate the presence of an acid or base in a
solution.
Litmus solution – It is a natural indicator. It is a purple dye extracted from Lichens.
Other examples are Red Cabbage and coloured petals of Petunia and turmeric.
Olfactory indicators : Show odour changes in acidic or basic media. E.g. onion and
Material downloaded from www.vidyakul.com.
, clove .
Acid – Base Indicators
S.No. Name of the Indicator Colour Change With Acid Colour Change with Base
A. Blue litmus solution To red No change
B. Red litmus solution No change To blue
C. Turmeric No change To red
D. Methyl orange To red To yellow
E. Phenolphthalein (colourless) No change To pink
Dilute Acid : A dilute acid contains a small amount of acid (lower concentration of
hydronium ions)and a large amount of water.
Concentrated Acid :A concentrated acid contains a large amount of acid (higher
concentration of hydronium ions)and a small amount of water.
Chemical Properties of Acids and Bases
1. Reaction with metal
Pop test : When a burning candle is brought near a test tube containing hydrogen gas
it burns with a ‘Pop’ sound. This test is conducted for examining the presence of
hydrogen gas.
Base + Metal Salt + Hydrogen
Material downloaded from www.vidyakul.com.
