Higher Secondary 1

IONIC EQUILIBRIUM: 

1. Ionic equilibrium: Equilibrium established between incompletely ionized chemical species in a solution of weak electrolyte is called Ionic Equilibrium.

2. Ionic equilibrium is not much talked about in the case of a solution containing strong electrolyte as the ions completely ionize in forward reaction process and since there is no reversible process, the condition of equilibrium doesn't arise. 

3. Ionic equilibrium is seen is the case of electrolytes which can be Acids, Bases or Salts.

4. Some concepts of Acids & Bases are as follows :

5. Meaning of conjugate base : 

HX + H2O ↔ X− + H3O+

In an acid-base reaction, you can recognize the conjugate base because it is an anion. For hydrochloric acid (HCl), this reaction becomes:

HCl + H2O ↔ Cl− + H3O+

Here, the chloride anion, Cl−, is the conjugate base.

Sulfuric acid, H2SO4 forms two conjugate bases as hydrogen ions are successively removed from the acid: HSO4- and SO42-.

6. Meaning of Conjugate acid: 

a conjugate acid is the acid member, HX, of a pair of compounds that differ from each other by gain or loss of a proton. A conjugate acid can release or donate a proton. 

When the base ammonia reacts with water, the ammonium cation is the conjugate acid that forms:

NH3(g) + H2O(l) → NH+4(aq) + OH−(aq)

7. Stronger the acid weaker will be it's conjugate base. 

8. Stronger the base weaker will be it's conjugate acid. 

9. Common Ion Effect: When an in the solution of a weak electrolyte any other electrolyte containing an ion that is already present then the dissociation of the weak electrolyte is suppressed. 

10. Le Chatelier's principle:  If a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change to re-establish an equilibrium. If a chemical reaction is at equilibrium and experiences a change in pressure, temperature, or concentration of products or reactants, the equilibrium shifts in the opposite direction to offset the change. This page covers changes to the position of equilibrium due to such changes and discusses briefly why catalysts have no effect on the equilibrium position.

11. pH and pOH denote the negative log of the concentration of hydrogen or hydroxide ions. High pH means that a solution is basic while high pOH means that a solution is acidic. Neutral solutions have pH and pOH of 7

12. List of formulas and relations which helps to solve numerical problems related to ionic equilibrium are as follows :

(i)