This document discusses indicators, acids, bases, and the reactions between them. It provides examples of natural and synthetic acid-base indicators and how they change color with pH. Acids are defined as sour substances that turn litmus red and donate hydrogen ions in water, while bases are defined as bitter substances that turn litmus blue and accept hydrogen ions in water. Common strong acids and bases are listed. The document also summarizes several acid-base reactions including neutralization and reactions with metals, carbonates, and oxides. It discusses the pH scale and importance of pH in everyday life. In the end, it briefly discusses the preparation and uses of several common salts.

2. Indicators:
 An indicator is a dye that changes colour with acids and bases
 Natural indicators
(litmus, turmeric)
 Synthetic indicators
(methyl orange, phenolphthalein)
 Olfactory indicators
( vanilla, onion, clove )

3. Sample Blue litmus Red litmus
Phenolptha
lein
Methyl
Orange
acid red no change colourless red
base no change
blue pink yellow

4. Acids and Bases in the laboratory
Acid
 It has sour taste
 It turns blue litmus to red
 Acid solutions conduct
current
 Strong Acids: HCL, H2SO4
 Weak Acids : CH3COOH
Base
 It has bitter taste
 It turns red litmus to blue
 Bases are electrolytes
 Strong Base: NaOH, KOH
 Weak Base: NH4OH

5. Action of Acids & Bases with Metals
Acid /Base + Metal Salt + Hydrogen gas
o Zn + H2SO4 ZnSO4 + H2
o Zn + 2NaOH Na2ZnO2 + H2
o chemical displacement

6. •Action of Metal Carbonates & Metal Hydrogen
carbonates with Acid
Carbonates + acid salt + carbon di oxide + water
Na2CO3 + 2HCl 2NaCl + H2O + CO2
NaHCO3 + 2HCl NaCl + H2O + CO2

7. Reaction of Metallic/Non metallic Oxides with Acids
# Metal Oxide + Acid Salt + Water
CuO + 2HCl CuCl2 + H2O
# Non metallic Oxide + base Salt + Water
Ca(OH)2 + CO2 CaCO3 + H2O
* products are similar to the products of neutralisation
• Metallic oxides are known as basic oxides
•Non-Metallic Oxides are called acidic oxides

9. What Happens to an Acid or a Base in a water solution?

10. Preparation of HCl

11. Acid and Bases in a water solution
 HCl + H2O H3O + Cl
 NaOH + H2O Na + OH
 HX + MOH MX + HOH (H2O)
 The process of dissolving an acid or base in water is a highly exothermic
 The process of mixing an acid and base with water is called dilution
- the dilution decreases the concentration of ions.

12. Strength of an acid and a base
 Universal Indicator is a mixer of several indicators
 It shows different colours at different concentrations H+ ions.
 pH Scale, used to measure the concentration of H+ ions.
 ‘p’ In pH stands for ‘potenz’ in German, meaning power.

14. Importance of pH in everyday life
 Our body works within the pH range of 7.0 to 7.8
 pH in our digestive system, antacids (Mg(OH)2)
 Tooth decay (corrosion of enamel) starts
when the pH of the mouth is <5.5…..to prevent
this tooth paste (basic)are used

15. What are present in acids and bases?
 hydrogen is common to all acids
 acids produce hydrogen ions(H+) in solutions
 these ions were responsible for their acidic properties
 hydroxyl ions (OH- ) are present in bases

16.  If the pH of rain water is <5.6, it is called acid rain
 Acid rain flows into the river and lowers the pH of the river
water
 Plants require a specific pH for their healthy growth
 Self defence by animals and plants ( honey bee injects HCOOH-
baking soda for relief from pain)

18. Neutralisation
Acid + Base Salt + Water

19. The process of dissolving an acid or a base
in water is a highly exothermic one.
The acid must always be added slowly to
water with constant stirring
A process of mixing an acid or base with
water is called dilute, it decreases the
concentration of ions.
C a r e o f a c i d s

20. F a m i l y o f S a l t s
pH = 7 Salts of strong acids and bases
pH > 7 Salts of strong base , weak acid
pH < 7 Salts of weak base , strong acid

21. • It is an important raw material for many substances
 NaOH ………. Causti soda
 Na2CO3 ……………. Washing Soda
 NaHCO3 ……………. Baking Soda
 CaOCl2 ………. Bleaching Powder
 CaSO4.1/2H2O … Plaster of Paris

22. • it is manufactured by the electrolysis of brine solution
• This process is known as Chlor –alkali process
• 2Nacl + 2H2O 2 NaOH + Cl2 + H2
• All three products are most useful
• H2(fuel-margarine ), Cl2 (cosmotics pesticides, water treatment)
NaOH ( de-greasing metals, soaps detergents and artificial paper)

23. it is manufactured by the action of CO2 with aq.NaCl
NaCl + H2O + CO2 + NH3 NH4Cl + NaHCO3
Uses : - for making baking powder( NaHCO3+tartaric acid)
- as an ingredient in antacids
- soda-acid fire extinguisher

24. it is obtained by heating baking soda
 2NaHCO3 Na2CO3 + H2O + CO2
Uses : - as cleansing agent
- for removing hardness of water
-in making of borax
- paper, glass, and soap industries

25. it is prepared by the action of Cl2 on dry s-lime
 Ca(OH)2 + Cl2 CaOCl2 + H2O
Uses : - for bleaching cotton ,wood pulp &
washed clothes
- as an oxidising agent
- for disinfecting drinking water

26. Are the crystals of salts really dry?
 CuSO4 . 5H2O - - - - blue vitriol
 FeSO4. 7H2O - - - - - green vitriol
 Na2CO3. 10H2O - - - - washing soda
 CaSO4. 2H2O - - - - gypsum

27. it is obtained on heating gypsum at 373K,
loses water molecule and becomes
Calcium sulphate hemi hydrate
 CaSO4. 2H2O CaSO4.1/2H2O + 1/2H2O
Uses : - for making toys, materials for
decoration and for making surfaces smooth