Chemistry Ch-10 Acid and Bases Igcse

1. Acids and Bases
By: Faiq & Rizan

2. Acids
Produce H+ ions in water
Have a sour taste
Break down metals
Formula starts with H
Poisonous and corrosive to skin
pH less than 7

3. Acid
turn blue litmus red
Dissolve in water to form solution which conduct electricity
React with reactive metal metals to form salt and hydrogen (explained)
Acids react with carbonates and hydrogen carbonates to form a salt,
water and carbon dioxide (explained)
Acids react with metal oxides and hydroxides to form a salt and water
only(explained)

4. Alkalis
Produce OH- ions in water
Have a bitter taste and a slippery feel
Break down fats and oils
Formula ends with OH
Poisonous and corrosive to skin
pH greater than 7

5. Alkalis
turn red litmus blue
React with acids to form salt and water only.(explained)
Heated with ammonium salts gives off ammonia gas.(explained)
React with a solution of one metal salt to give another metal salt
and metal hydroxide.(explained)

6. pH scale
Acid have pH of <7
Alkalis have pH of >7

7. Theories of acids and
bases

8. Arrhenius Concept of Acids and Bases
According to the Arrhenius concept of acids and bases, an acid is
a substance that, when dissolved in water, increases the
concentration of hydronium ion (H3O+).
Remember, however, that the aqueous hydrogen ion is actually
chemically bonded to water, that is, H3O+.

9. Arrhenius Concept of Acids and Bases
A base, in the Arrhenius concept, is a substance
that, when dissolved in water, increases the
concentration of hydroxide ion, OH-(aq).

10. Bronsted-Lowry Acid and Bases
Bronsted-Lowry Acid can donate a proton
Bronsted-Lowry Base can accept a proton
Must contain a non-bonding pair of electrons
Conjugate base of an acid is the species remaining after
the acid has lost a proton

11. Bronsted-Lowry Acid and Bases
Conjugate acid is the species formed after the base has
accepted a proton
HCl + H2O ↔ H3O+ + Cl-
 Water is conjugate base of H3O+ and Cl- is conjugate
base of HCl

12. Bronsted-Lowry Acid and Bases
Water can act both as acid and base. Amphiprotic
Strong acids have weak conjugate base
Weak acids have strong conjugate base
 ACID: Ethanol (C2H5OH) =>weak
 CONJUGATE BASE: Ethoxide ion (C2H5O-) => strong

13. Lewis Acids and Bases
Bases can donate a pair of electrons
Acids can accept a pair of electrons
 Covalent bond is formed
Many Lewis Acids don’t contain hydrogen

14. Properties of Acids and
Bases

15. Properties of Acids and Bases
Neutralization reaction with bases
With hydroxides to form salt and water
 CH3COOH + NaOH  NaCH3COO + H2O
With metal oxides to form a salt and water
 H2SO4 + CuO  CuSO4 + H2O
With ammonia to form salt
 HCl + NH3  NH4Cl

16. Properties of Acids and Bases
With reactive metals to form salt and hydrogen
 2HCl + Mg  MgCl2 + H2
With carbonates to form salt, CO2, water
 2HCl + CaCO3  CaCl2 + CO2 + H2O
With hydrogen carbonates to form salt, CO2, water
 HCl + NaHCO3  NaCl + CO2 + H2O

17. Strong Acids and Bases
Strong acid and base is completely dissociated (ionized) into its
ions in aqueous solutions
Strong acids
 HCl (Hydrochloric acid)
 HNO3 (Nitric Acid)
 H2SO4 (Sulfuric Acid)

18. Strong Acids and Bases
Strong bases
 NaOH (Sodium Hydroxide)
 KOH (Potassium Hydroxide)
 Ba(OH)2 (Barium Hydroxide)

19. Weak Acids and Bases
Weak acids and bases is slightly dissociated into their ions in
aqueous solution
Weak acids
 CH3COOH (Ethanoic Acid)
 H2CO3(Carbonic acid)

20. Weak Acids and Bases
Weak bases
 NH3 (Ammonia)
 C2H5NH2 (Amino ethane)

21. Acidic oxides
Acidic oxides are the oxides of non-metals. When combined with
water, they produce acids, e.g.,
Acidic oxides are, therefore, known as acid anhydrides, e.g.,
Sulphur dioxide is sulphurous anhydride; Sulphur trioxide is
sulphuric anhydride.

22. Basic oxides
Basic oxides are the oxides of metals. If soluble in water they react with
water to produce hydroxides (alkalis).
Basic oxides do not reacts with alkalis.
Examples:
 CaO + H2O Ca(OH)2
 MgO + H2O Mg(OH)2

23. Amphoteric oxides
Amphoteric oxides are metallic oxides, which show both basic as
well as acidic properties. When they react with an acid, they
produce salt and water, showing basic properties. While reacting
with alkalis they form salt and water showing acidic properties

24. Neutral oxides
These are the oxides, which show neither basic nor acidic
properties, that is, they do not form salts when reacted with acids
or bases, e.g., carbon monoxide (CO); nitrous oxide (N2O); nitric
oxide (NO), etc., are neutral oxides.

25. Thank You for reading and
hope u all understand
