ACHIEVER’S COACHING
SCIENCE
YESHPAL SIR 9039056548
ACID BASE AND SALTS
1. Acids: Acids are sour in taste, turn blue litmus red and give H+ ion (hydronium ions in solution. e.g. HCl,
H2SO4, HNO3 etc
2. Bases: Bases are bitter in taste, have soapy touch, turns red litmus blue and give hydroxide ions (OH -) in
solution. Example – NaOH, KOH etc
3. Salts: - A salt is a compound which is formed by neutralization reaction between an acid and base. For
example, sodium chloride is formed by reaction between hydrochloric acid and sodium hydroxide.
Acid + base ----------Salt + water
HCl+NaOH ------- NaCl+H2O
4. Indicators - Indicators are substances which indicate the acidic or basic nature of the solution by their
colour change. The colour of some acid-base indicators in acidic and basic medium are given below
INDICATORS COLOUR IN ACIDIC COLOUR IN BASIC
MEDIUM MEDIUM
1. Litmus Solution Red Blue
2. Methyl Orange Pink Orange
3. Phenolphthalein Colourless Pink
4. Methyl Red Yellow Red
5 Chemical properties of acids
(i) Acids react with active metals to give hydrogen gas.
Zn + H2SO4-------- ZnSO4 + H2
(ii) Acids react with metal carbonate and metals hydrogen carbonate to give carbon dioxide.
Na2CO3 + HCl -------- > NaCl + CO2 + H2O
NaHCO3+HCl ------- NaCl + H2O+CO2
(iii) Acids react with bases to give salt and water. This reaction is called neutralization reaction.
NaOH +HCl ------ NaCl + H2O
(iv) Acids react with metals oxides to give salt and water.
CuO + H2SO4 ------ CuSO4 + H2O
6 Chemical properties of Bases-
1. Reaction with Metals – Certain metals such as Zinc, Aluminum, Tin
react with Alkali solutions on heating and hydrogen gas is evolved
2NaOH + Zn → Na2ZnO2 + H2
2. Reaction with acids – Bases react with acids to form salt and water.
KOH + HCl → KCl + H2O
3. Reaction with Non – metallic oxides –
Non - metallic oxides are
generally acidic in nature. They react with bases to form salt and water.
2NaOH + CO2 → Na2CO3 + H2O
7. Strong and Weak Acids
An acid which completely dissociates into ions in aqueous solution is called strong acid such as HCl, H 2SO4,
and HNO3 etc. Weak acids are those which are weakly dissociated in its aqueous solution such as
CH3COOH, H2CO3, and HCN etc. ]
8. Strong and Weak Bases
A base such as NaOH or KOH which is completely dissociated in aqueous solution is called a strong base.
On the other hand a base which is weakly dissociated such as NH4 OH in its aqueous solution is called a
weak base.
11. Some Important Chemical Compounds
(a) Common Salt (NaCl)
Sodium chloride is known as common salt .Its main source is sea water. It also exists in the form of rocks
and sodium chloride obtained from rocks is called rock salt. Common salt is an important component of our
food. It is also used for preparing sodium hydroxide, baking soda, washing soda etc.
(b) Sodium Hydroxide or Caustic Soda (NaOH)
Sodium hydroxide is prepared by passing electricity through an aqueous solution of sodium chloride (also
known as brine).
2NaCl (aq) + 2H2O (l)--------- 2NaOH (aq) + Cl2 (g) + H2 (g)
This process is known as chlor -alkali process due to the formation of chlorine and sodium hydroxide (an
alkali) as the products.
Properties –
SCIENCE
YESHPAL SIR 9039056548
ACID BASE AND SALTS
1. Acids: Acids are sour in taste, turn blue litmus red and give H+ ion (hydronium ions in solution. e.g. HCl,
H2SO4, HNO3 etc
2. Bases: Bases are bitter in taste, have soapy touch, turns red litmus blue and give hydroxide ions (OH -) in
solution. Example – NaOH, KOH etc
3. Salts: - A salt is a compound which is formed by neutralization reaction between an acid and base. For
example, sodium chloride is formed by reaction between hydrochloric acid and sodium hydroxide.
Acid + base ----------Salt + water
HCl+NaOH ------- NaCl+H2O
4. Indicators - Indicators are substances which indicate the acidic or basic nature of the solution by their
colour change. The colour of some acid-base indicators in acidic and basic medium are given below
INDICATORS COLOUR IN ACIDIC COLOUR IN BASIC
MEDIUM MEDIUM
1. Litmus Solution Red Blue
2. Methyl Orange Pink Orange
3. Phenolphthalein Colourless Pink
4. Methyl Red Yellow Red
5 Chemical properties of acids
(i) Acids react with active metals to give hydrogen gas.
Zn + H2SO4-------- ZnSO4 + H2
(ii) Acids react with metal carbonate and metals hydrogen carbonate to give carbon dioxide.
Na2CO3 + HCl -------- > NaCl + CO2 + H2O
NaHCO3+HCl ------- NaCl + H2O+CO2
(iii) Acids react with bases to give salt and water. This reaction is called neutralization reaction.
NaOH +HCl ------ NaCl + H2O
(iv) Acids react with metals oxides to give salt and water.
CuO + H2SO4 ------ CuSO4 + H2O
6 Chemical properties of Bases-
1. Reaction with Metals – Certain metals such as Zinc, Aluminum, Tin
react with Alkali solutions on heating and hydrogen gas is evolved
2NaOH + Zn → Na2ZnO2 + H2
2. Reaction with acids – Bases react with acids to form salt and water.
KOH + HCl → KCl + H2O
3. Reaction with Non – metallic oxides –
Non - metallic oxides are
generally acidic in nature. They react with bases to form salt and water.
2NaOH + CO2 → Na2CO3 + H2O
7. Strong and Weak Acids
An acid which completely dissociates into ions in aqueous solution is called strong acid such as HCl, H 2SO4,
and HNO3 etc. Weak acids are those which are weakly dissociated in its aqueous solution such as
CH3COOH, H2CO3, and HCN etc. ]
8. Strong and Weak Bases
A base such as NaOH or KOH which is completely dissociated in aqueous solution is called a strong base.
On the other hand a base which is weakly dissociated such as NH4 OH in its aqueous solution is called a
weak base.
11. Some Important Chemical Compounds
(a) Common Salt (NaCl)
Sodium chloride is known as common salt .Its main source is sea water. It also exists in the form of rocks
and sodium chloride obtained from rocks is called rock salt. Common salt is an important component of our
food. It is also used for preparing sodium hydroxide, baking soda, washing soda etc.
(b) Sodium Hydroxide or Caustic Soda (NaOH)
Sodium hydroxide is prepared by passing electricity through an aqueous solution of sodium chloride (also
known as brine).
2NaCl (aq) + 2H2O (l)--------- 2NaOH (aq) + Cl2 (g) + H2 (g)
This process is known as chlor -alkali process due to the formation of chlorine and sodium hydroxide (an
alkali) as the products.
Properties –
