It discusses about equilibrium,chemical equilibrium,ionic equilibrium,electrolytes,types of electrolyte,s degree of dissociation,percent dissociation.

1. Chemistry
12th science
3. IONIC EQUILIBRIA
Marks 4/6
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2. What is equilibrium?
Can you re call?
Balanced state at which certain measurable properties such as
pressure, density, colour, concentration etc. do not changes with
time.
Physical equilibrium –involves only physical change
Chemical equilibrium –involves chemical change
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3. Can you re call?
What is chemical equilibrium?
Chemical Equilibrium is a state of chemical reaction at
which rate of forward and reverse reactions are equal and
there is no further change in concentration of reactant and
product..
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4. Can you re call?
What are electrolytes ?
.
Electrolytes:-
The substances which in their aqueous solutions
dissociate or ionizes to form cations and anions are
called electrolytes. e.g. NaCl, HCl, CH3COOH
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5. Can you re call?
What are non electrolytes?
Non electrolytes:- Those substances which do not ionizes
and exist as molecules in aqueous solutions are called non
electrolytes e. g.
glucose- C6H12O6
cane sugar- C12H22O11
Urea- NH2CONH2
Methanol -CH3OH
carbon tetra chloride- CCl4
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7. 3.2 Types of electrolytes :-
Based on their extent of ionization in dilute aq.
Solutions electrolytes are classified as
Strong electrolytes and Weak electrolytes.
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8. 3.2.1 Strong electrolytes:-
The electrolytes ionizing completely or almost completely are
strong electrolytes.
Strong acids, Strong bases, Salts H2SO4, NaOH, NaCl
HCl(aq)→H+(aq) +CL- (aq)
Strong acid
NaOH(aq)→Na+(aq) +OH- (aq)
Strong base
NaCl(aq)→Na+(aq) +CL- (aq)
salt
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9. 3.2.1 Weak electrolytes:-
The electrolytes dissociates to smaller extent in aq. solution are
weak electrolytes.
weak acids, weak bases.
CH3COOH, NH4OH
NH4OH(aq) NH4
+(aq) +OH- (aq)
Weak base
CH3COOH(aq) CH3COO-(aq) + H+ (aq)
Weak acid
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10. Sr.
No.
Strong acids Strong
bases
Salts Weak acids weak
bases
1 Per chloric acid
HClO4
Sodium
hydroxide
NaOH
Sodium chloride
NaCl
Acetic acid
CH3COOH
Ammonium
hydroxide
NH4OH
2 Sulphuric acid
H2SO4
Potassium
hydroxide
KOH
Potassium Nitrate
KNO3
Hydrocyanic acid
HCN
Ammonia
NH3
3 Hydro iodic acid HI Coppersulphate
CuSO4
Hydro fluoric acid
HF
Ethylammine
C2H5NH2
4 Hydrobromic acid HBr Silvernitrate
AgNo3
Ammonium acetate
CH3COONH4
Carbonic acid
H2CO3
5 Hydrochloric acid HCl Boric acid
H3BO3
6 Nitric acid
HNO3
Nitrous acid
HNO2
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11. Which of the following is a strong electrolytes?
HF acid
AgCl salt
CuSO4 salt
CH3COONH4 salt
H3PO4 acid
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12. Ionic Equilibrium:-
The equilibrium between ions and un ionized molecules in
solution is called ionic equilibrium.
Equilibrium exists only for weak electrolytes as they do not
under go complete ionization, such as acetic acid
NH4OH(ammonium hydroxide) etc.
CH3COOH (aq) CH3COO-(aq) + H+ (aq)
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13. 3.2.3 Degree of dissociation(α)
The degree of dissociation of an electrolyte is defined as a
fraction of total number of moles of the electrolyte that
dissociates into its ions when equilibrium is attained.
It is denoted by symbol α
α = number of moles dissociated
total number of moles
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14. α = number of moles dissociated
total number of moles
e.g . 1 mole of weak electrolyte ionizes and only 0.05 mols
under go ionization
α = 0.05
1
= 0.05
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15. Percent dissociation = α × 100
% dissociation= 0.05 (α )× 100
= 5 %
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16. If C is molar concentration of an electrolyte
then equilibrium concentration of cation or anion is (α × C)
mol/dm3
e.g. = 0.05 × 0.1
= 0.005 mol/dm3
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17. Thank You
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