ACIDS BASES AND SALTS
KEY POINTS:
1. Conjugate acid of a base:
The positively charged ion produced by the acceptance of a proton by a base is the conjugate acid of the base.
2. Conjugate base of the acid:
The negatively charged ions or a neutral species produced by the release of a proton is the conjugate base of the compound releasing the proton.
3. Lowery-Bronsted concept of acids and bases:
Acids:
Acids are those species that give proton or have a tendency to give proton.
Bases:
Bases are those species that accept protons or have the tendency to accept protons.
4. pH of the solution:
The negative log of [H+] is called the pH of the solution.
5. pKw:
It is the negative log of the dissociation constant of water.
6. Leveling effect:
Some strong acids have nearly equal strength in an aqueous solution. Such a property of acids is called leveling effect.
7. Buffer solution:
Substances that resist change in pH of a solution when a small amount of acid or a base is added to them are called buffer solutions.
8. Acid-base indicator:
A substance (a weak acid or a weak base) that has a different colour in an acid or weak base solution is called an acid-base indicator.
9. Titration:
Titration is a method to find the volume of a standard solution required to react completely with the known volume of another solution under analysis.
10. pKa:
pKa is defined as the negative logarithm of Ka.
11. pKb:
pKb is defined as the negative logarithm of Kb.
12. Lewis concept of acid and base:
Acid is a substance that can accept a pair of electrons and base is a substance that can donate an electron pair.
12. Buffer Action:
The property of the buffer solution is to maintain its pH when a small amount of acid or base is added to it.
13. Buffer capacity:
The capacity of a buffer to maintain constant pH is called its buffer capacity.
14. Hydrolysis:
The reaction of cations and anions of slats with water is called hydrolysis.
15. Leveling effect:
The strength of all strong acids and bases becomes equal to the acidic and basic characteristics of solvent. This effect is called leveling effect.