Here Discuss about Acid Base and Salt for Class 10 and CBSE lesson & NCERT. First discuss Acids then Bases then salts.
Acid:
In the beginning acid defined as – they have hydrogen as their constituent element in the form of proton (H+).
The word ‘acid’ derived from the Latin word acidus, means sour. It changes the blue litmus paper into red colour.
Definition : Compounds which have one or more hydrogen atom and produce hydronium ions (H₃O+) in aqueous solution as the only positively charged ions are called acids.
Classification of Acids:
A. On the basis of their source acid are two types (i) Organic acids example: oxalic acid, acetic acid (ii) Inorganic acid example: hydrochloric acid, sulphuric acid.
B. On the basis of their strength acids are two types (i) Strong acid: it rapidly ionised in aqueous solution and produce high concentration of hydronium ions. Example: hydrochloric acid, sulphuric acid etc. (ii) Weak Acid: it is partially ionised in aqueous solution and produce lesser quantity of hydronium ions as well as molecules. Example: acetic acid, carbonic acid etc.
C. On the basis of their concentration acids are two types (i) Concentrated acid: An acid which contains a very small quantity of water or no water. (ii) Dilute acid: An acid which contain large quantity of water than it.
D. On the basis of their basicity (i) Monobasic acids: in aqueous solution they produce one hydronium ion. Example: hydrochloric acid, nitric acid, acetic acid etc. (ii) Dibasic acids: in aqueous solution they produce two hydronium ions. Example: sulphuric acid, oxalic acid, carbonic acid etc. (iii) Tribasic acid: in aqueous solution they produce three hydronium ions. Example: phosphoric acid, phosphorous acid etc. (iv) Silicic acid H₄SiO₄ has basicity four.
Chemical Properties of acids:
(i) Chemical reaction of acids with metals:
When acids react with metals, they produce hydrogen gas and their respective salt.
Acid + Metal → Hydrogen gas + Salt
Example:
When hydrochloric acid reacts with zinc metal or magnesium metal forms hydrogen gas and either zinc chloride or magnesium chloride.
Zn + 2HCl → ZnCl₂ + H₂↑
Mg + 2HCl → MgCl₂ + H₂↑
When iron reacts with sulphuric acid produce hydrogen gas as well as iron sulphate.
Fe + H₂SO₄ → H₂↑ + FeSO₄
Identification test for hydrogen gas:
When gas is produced during reaction between acid and metal, we can test it by bringing a candle near it. If the gas is burn with pop sound then we can said that the gas is hydrogen. One of the characteristic property of hydrogen gas is it burn with pop sound.
Reaction with Carbonates:
When acid react with metal carbonates, its produce carbon dioxide, respective salt and water.
Acid + Metal Carbonate → Carbon dioxide + Salt + Water
Examples:
(a)When hydrochloric acid reacts with sodium chloride produce carbon dioxide, sodium chloride and water.
Na₂CO₃ + 2HCl → 2NaCl + CO₂↑ + H₂O
(b) When hydrochloric acid reacts with magnesium carbonate produces carbon dioxide, magnesium chloride and water.
MgCO₃ + 2HCl → CO₂↑ + MgCl₂ + H₂O
(c) Carbon dioxide, calcium chloride and water is formed when reaction take place between hydrochloric acid and calcium carbonate.
CaCO₃ + 2HCl → CaCl₂ + CO₂↑ + H₂O
(d) Calcium sulphate, carbon dioxide and water are formed when the reaction undergoes between sulphuric acid and calcium carbonate.
CaCO₃ + 2HCl → CaSO₄ + CO₂↑ + H₂O
(e) Sodium sulphate, carbon dioxide and water are formed when the reaction undergoes between sodium carbonate and sulphuric acid.
Na₂CO₃ + H₂SO₄ → Na₂SO₄ + CO₂↑ + H₂O
(f) Sodium nitrate, carbon dioxide and water is formed when the reaction take place between nitric acid and sodium carbonate.
2HNO₃ + Na₂CO₃ → NaNO₃ + CO₂↑ + H₂O
Reaction between acid and bicarbonate:
When acid react with bicarbonate forms carbon dioxide, respective salt and water.
Acid + Metal bicarbonate → Salt + Carbon dioxide + Water
Examples:
(a) Sodium chloride, carbon oxide and water is formed when the reaction take place between sodium bicarbonate and hydrochloric acid.
NaHCO₃ + HCl → NaCl + CO₂↑ + H₂O
(b) Sodium sulphate, carbon dioxide and water are formed when sulphuric acid reacts with sodium bicarbonate.
2NaHCO₃ + H₂SO₄ → Na₂SO₄ + 2CO₂ + H₂O
[Note: Sodium chloride is known by various names like sodium hydrogen carbonate, baking soda, baking powder, bread soda and bicarbonate of soda.
Reaction with Sulphites and bisulphites:
When acids react with sulphites or bisulphites of metals forms sulphur dioxide, respective salt and water.
Examples:
When hydrochloric acid reacts with calcium sulphite form calcium chloride, sulphur dioxide and water.
And when hydrochloric acid reacts with calcium bisulphites forms sulphur dioxide, sodium chloride and water.
CaSO₃ + 2HCl → CaCl₂ + SO₂↑ + H₂O
NaHSO₃ + HCl → NaCL + SO₂↑ + H₂O
Acid:
In the beginning acid defined as – they have hydrogen as their constituent element in the form of proton (H+).
The word ‘acid’ derived from the Latin word acidus, means sour. It changes the blue litmus paper into red colour.
Definition : Compounds which have one or more hydrogen atom and produce hydronium ions (H₃O+) in aqueous solution as the only positively charged ions are called acids.
Classification of Acids:
A. On the basis of their source acid are two types (i) Organic acids example: oxalic acid, acetic acid (ii) Inorganic acid example: hydrochloric acid, sulphuric acid.
B. On the basis of their strength acids are two types (i) Strong acid: it rapidly ionised in aqueous solution and produce high concentration of hydronium ions. Example: hydrochloric acid, sulphuric acid etc. (ii) Weak Acid: it is partially ionised in aqueous solution and produce lesser quantity of hydronium ions as well as molecules. Example: acetic acid, carbonic acid etc.
C. On the basis of their concentration acids are two types (i) Concentrated acid: An acid which contains a very small quantity of water or no water. (ii) Dilute acid: An acid which contain large quantity of water than it.
D. On the basis of their basicity (i) Monobasic acids: in aqueous solution they produce one hydronium ion. Example: hydrochloric acid, nitric acid, acetic acid etc. (ii) Dibasic acids: in aqueous solution they produce two hydronium ions. Example: sulphuric acid, oxalic acid, carbonic acid etc. (iii) Tribasic acid: in aqueous solution they produce three hydronium ions. Example: phosphoric acid, phosphorous acid etc. (iv) Silicic acid H₄SiO₄ has basicity four.
Chemical Properties of acids:
(i) Chemical reaction of acids with metals:
When acids react with metals, they produce hydrogen gas and their respective salt.
Acid + Metal → Hydrogen gas + Salt
Example:
When hydrochloric acid reacts with zinc metal or magnesium metal forms hydrogen gas and either zinc chloride or magnesium chloride.
Zn + 2HCl → ZnCl₂ + H₂↑
Mg + 2HCl → MgCl₂ + H₂↑
When iron reacts with sulphuric acid produce hydrogen gas as well as iron sulphate.
Fe + H₂SO₄ → H₂↑ + FeSO₄
Identification test for hydrogen gas:
When gas is produced during reaction between acid and metal, we can test it by bringing a candle near it. If the gas is burn with pop sound then we can said that the gas is hydrogen. One of the characteristic property of hydrogen gas is it burn with pop sound.
Reaction with Carbonates:
When acid react with metal carbonates, its produce carbon dioxide, respective salt and water.
Acid + Metal Carbonate → Carbon dioxide + Salt + Water
Examples:
(a)When hydrochloric acid reacts with sodium chloride produce carbon dioxide, sodium chloride and water.
Na₂CO₃ + 2HCl → 2NaCl + CO₂↑ + H₂O
(b) When hydrochloric acid reacts with magnesium carbonate produces carbon dioxide, magnesium chloride and water.
MgCO₃ + 2HCl → CO₂↑ + MgCl₂ + H₂O
(c) Carbon dioxide, calcium chloride and water is formed when reaction take place between hydrochloric acid and calcium carbonate.
CaCO₃ + 2HCl → CaCl₂ + CO₂↑ + H₂O
(d) Calcium sulphate, carbon dioxide and water are formed when the reaction undergoes between sulphuric acid and calcium carbonate.
CaCO₃ + 2HCl → CaSO₄ + CO₂↑ + H₂O
(e) Sodium sulphate, carbon dioxide and water are formed when the reaction undergoes between sodium carbonate and sulphuric acid.
Na₂CO₃ + H₂SO₄ → Na₂SO₄ + CO₂↑ + H₂O
(f) Sodium nitrate, carbon dioxide and water is formed when the reaction take place between nitric acid and sodium carbonate.
2HNO₃ + Na₂CO₃ → NaNO₃ + CO₂↑ + H₂O
Reaction between acid and bicarbonate:
When acid react with bicarbonate forms carbon dioxide, respective salt and water.
Acid + Metal bicarbonate → Salt + Carbon dioxide + Water
Examples:
(a) Sodium chloride, carbon oxide and water is formed when the reaction take place between sodium bicarbonate and hydrochloric acid.
NaHCO₃ + HCl → NaCl + CO₂↑ + H₂O
(b) Sodium sulphate, carbon dioxide and water are formed when sulphuric acid reacts with sodium bicarbonate.
2NaHCO₃ + H₂SO₄ → Na₂SO₄ + 2CO₂ + H₂O
[Note: Sodium chloride is known by various names like sodium hydrogen carbonate, baking soda, baking powder, bread soda and bicarbonate of soda.
Reaction with Sulphites and bisulphites:
When acids react with sulphites or bisulphites of metals forms sulphur dioxide, respective salt and water.
Examples:
When hydrochloric acid reacts with calcium sulphite form calcium chloride, sulphur dioxide and water.
And when hydrochloric acid reacts with calcium bisulphites forms sulphur dioxide, sodium chloride and water.
CaSO₃ + 2HCl → CaCl₂ + SO₂↑ + H₂O
NaHSO₃ + HCl → NaCL + SO₂↑ + H₂O