The document discusses acids and bases. It defines acids as compounds that yield hydrogen ions (H+) when dissolved in water. It provides examples of common acids like hydrochloric acid, nitric acid, sulfuric acid, etc. and describes how each one reacts with water to produce hydrogen ions. The document also classifies acids based on origin, strength, concentration, and number of hydrogen ions produced. Similarly, it defines bases as compounds that yield hydroxide ions (OH-) in water, provides examples, and describes their classification based on strength and concentration.

1. BY: MS VEENU GUPTA
(PGT CHEMISTRY)
APS RAKHMUTHI

2. ACIDS
Acid is a compound which
yields hydrogen ion (H+),
when dissolved in water.

3. Examples of commonly used acids
Hydrochloric acid (HCl)
Nitric acid (HNO3)
Sulphuric acid (H2SO4)
Carbonic acid (H2CO3)
Phosphoric acid (H3PO4)
Acetic acid (CH3COOH)

4. ACTION OF ACIDS IN WATER
 Hydrochloric acid (HCl) gives hydrogen ion (H+) and
chloride ion (Cl–) when it is dissolved in water.
HCl + H2O → H3O+ + Cl-
 Nitric acid (HNO3) gives hydrogen ion (H+) and
nitrate ion (NO3
-) when it is dissolved in water.
HNO3 + H2O → H3O+ + NO3
-
 Sulphuric acid (H2SO4) gives hydrogen ion (H+) and
sulphate ion (SO4
2-) when it is dissolved in water.
H2SO4 + H2O → H3O+ + SO4
2-

5.  Carbonic acid (H2CO3) gives hydrogen ion (H+) and
carbonate ion (CO3
2-) when it is dissolved in water.
H2CO3 + H2O → H3O+ + CO3
2-
 Acetic acid (CH3COOH) gives acetate ion (CH3COO–)
and hydrogen ion (H+).
CH3COOH + H2O → CH3COO– + H3O+
 Phosphoric acid (H3PO4) gives hydrogen ion (H+) and
phosphate ion (PO4
3-) when it is dissolved in water.
H3PO4 + H2O → H3O+ + PO4
3-
 Thus, those compound which yields hydrogen
ion (H+), when dissolved in water are called
acids.

6. CHEMISTRY OF ACIDS IN WATER:
 When an acid is dissolved in water, it dissociates hydrogen. The
dissociation of hydrogen ion in aqueous solution is the common property
in all acids. Because of the dissociation of hydrogen ion in aqueous
solution, an acid shows acidic behaviour.
Examples:
Hydrochloric acid (HCl) gives hydrogen ion (H+) and chloride ion (Cl–)
when it is dissolved in water.
Acetic acid (CH3COOH) gives acetate ion (CH3COO–) and hydrogen ion (H+).
 It conducts electricity.
 Decrease in H30+ ions concentration per unit volume results in formation
of dilute acids.

7. NATURE OF RXN OF ACIDS IN WATER
 Acids when dissolved in water,they release a large amount of
heat as it is a highly exothermic reaction. So to make acidic
solution, acids must be added drop wise into water with
constant stirring, so that the heat generated spreads over in
water.
 Acids produce H+ ions when dissolved in water. H+ ions
cannot exist alone. They combine with water molecule (H2O)
to form H3O+ (hydronium ions).
 HCl + H2O → H3O+ + Cl–

8. PROPERTIES OF ACIDS
 - Produce hydrogen ions [H+] in H2O.
 – Sour taste.
 – Turn blue litmus red.
 – Act as electrolytes in Solution.
 – Neutralize solutions carrying hydroxide ions.
 – React with several metals releasing Hydrogen gas.
 – React with carbonates releasing CO2 (g)
 – Destroy body tissues.
 – corrode metal surface quickly.

9. CLASSIFICATION OF ACIDS
ON THE BASIS OF ORIGIN
ON THE BASIS OF STRENGTH
ON THE BASIS OF CONCENTRATION
ON THE BASIS OF HYDROGEN ION

10. ON THE BASIS OF ORIGIN
 Organic acids: Acids derived from living organisms like
plants and animals . For example: citric acid is present in
fruits, acetic acid present in vinegar, oxalic acid present
in tomato, tartaric acid present in tamarind, lactic acid
present in sour milk and curd.
 Mineral acids: They are also called inorganic acids. They
are dangerous Example sulphuric acid (H2SO4),
hydrochloric acid (HCl) etc.

11. SOURCES OF ORGANIC ACIDS
Organic Acids Sources
Acetic acid Vinegar
Ascorbic acid Guava, amla
Citric acid Lemon, orange and other citrus fruits
Lactic acid Sour milk, curd
Methanoic acid Ant sting, nettle sting
Oxalic acid Tomato
Tartaric acid Tamarind

12. ON THE BASIS OF STRENGTH
 Strong acids: Completely dissociate into its ions in
aqueous solutions.
 Example: Nitric acid (HNO3), sulphuric acid (H2SO4),
hydrochloric acid (HCl).
 Weak acids: Weak acids are those acids which do not
completely dissociate into its ions in aqueous
solutions.
 For example: carbonic acid (H2CO3), acetic acid
(CH3COOH)

13. ON THE BASIS OF CONCENTRATION
 Dilute acids: Have a low concentration of acids in
aqueous solutions. Decrease in H+ ions single
concentration per unit volume results in formation
of dilute acids.
 Concentrated acids: Have a high concentration of
acids in aqueous solutions. Increase in H+ ions single
concentration per unit volume results in formation
of conc. acids.

14. ON THE BASIS OF HYDROGEN ION
 Monoprotic acid – Such type of acid produces one
mole of H+ ions per mole of acid. e.g., HCl , HNO3
 Diprotic acid – They can produce two moles of H+
ions per mole of acid, e.g., H2SO4.
 Triprotic acid – They produce three moles of H+ ions
per mole of acid, e.g., H3PO4.
 Polyprotic – They can produce more than three H+
ions per mole of acid.

15. BASES
 Bases are bitter in taste, have soapy touch, turn red
litmus blue and give hydroxide ions (OH–) in
aqueous solution.
 Examples:
 Sodium hydroxide (caustic soda) – NaOH
Calcium hydroxide – Ca(OH)2
Potassium hydroxide (caustic potash) – (KOH)

16. ACTION OF BASES ON WATER
 Bases generate OH- ions in water
1. NaOH (aq) + H2O → Na+ (aq) + OH– (aq)
2. KOH (aq) + H2O → K+ (aq) + OH– (aq)
3. Ca(OH)2 (aq) + H2O → Ca2+ (aq) + OH– (aq)
4. NH3 (g) + H2O (l) →NH4OH (aq)
NH4OH (aq) → NH4
+ (aq) + OH- (aq)

17. ALKALI VS BASES
 All bases do not dissolve in water. An alkali is a base that
dissolves in water.
Common alkalis are:
 NaOH -Sodium hydroxide
 KOH - Potassium hydroxide
 Ca(OH)2 -Calcium hydroxide
 NH4OH -Ammonium hydroxide
 Note : All alkalis are bases but all bases are not alkalis.

18. PROPERTIES OF BASES
 - Produce hydroxide ions [OH –] in H2O.
 – Water soluble bases are called alkalies.
 – Bitter Taste
 – Turn Red Litmus blue.
 – Act as electrolytes in Solution.
 – Neutralize solutions containing H+ ions.
 – Have a slippery, ‘soapy’ feel.
 – Dissolve fatty material.

19. CLASSIFICATION OF
BASES

20. ON THE BASIS OF
STRENGTH
 Strong bases: Strong bases are those bases
which completely dissociate into its ions in
aqueous solutions. Example: sodium
hydroxide (NaOH), potassium hydroxide
(KOH).
 Weak bases: Weak bases are those bases
which do not completely dissociate into its
ions in aqueous solutions. For example:
ammonium hydroxide (NH4OH).

21. ON THE BASIS OF CONCENTRATION
 Dilute bases: Have a low concentration of alkali in
aqueous solutions. Decrease in OH– ions single
concentration per unit volume results in formation
of dilute bases.
 Concentrated bases: Have a high concentration of
alkali in aqueous solutions. Increase in OH– ions
single concentration per unit volume results in
formation of conc. bases.

22. CHEMISTRY OF BASES IN WATER:
 Bases produce OH– ions when dissolved in water. Bases
which are soluble in water are called alkalis. It conducts
electricity.
 Decrease in OH– ions single concentration per unit volume
results in formation of dilute bases.
 Bases when dissolved in water release large amount of heat
as it is a exothermic reaction. So to make basic solution, base
must be added drop wise into water with constant stirring,
so that the heat generated spreads over in water.