CBSE CLASS 10 CHEMISTRY

1. ACIDS , BASES AND
SALTS .
CBSE CLASS 10 - CHEMISTRY
NITYA SHARMA

2. INDICATORS
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3. INDICATORS
INDICATORS ARE SUBSTANCES WHICH INDICATE
WHETHER A GIVEN SUBSTANCE IS A N ACID OR A BASE
BY CHANGE IN COLOUR OR SMELL.
TYPES OF INDICATORS :
1. NATURAL INDICATORS
2. SYNTHETIC INDICATORS
3. OLFACTORY INDICATORS

4. NATURAL INDICATORS ;
INDICATORS ARE OBTAINED FROM NATURE AND INDICATE BY CHANGING THE COLOUR.
1. TURMERIC
2. LITMUS
3. RED CABBAGE
4. HYDRANGEA FLOWER PETALS
SYNTHETIC INDICATORS;
INDICATORS ARE MANUFACTURED CHEMICALLY IN FACTORIES OR INDUSTRIES .
1. PHENOLPHTHALEIN
2. METHYL ORANGE
OLFACTORY INDICATORS;
INDICATORS WHICH DETECT AN ACID OR BASE BY A CHANGE IN SMELL.
1. ONION JUICE
2. VANILLA EXTRACT
3. CLOVE OIL

5. ACIDS AND
BASES
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6. ARRHENIUS THEORY -- AN ACID IS A SUBSTANCE THAT DISSOCIATES AND PRODUCES HYDROGEN ION ( H+
) OR HYDRONIUM ION ( HзO + ) WHEN DISSOLVED IN WATER .
LEWIS THEORY -- THE SUBSTANCES OR ELEMENTS WHICH HAVE A TENDENCY TO ACCEPT ONE LONE PAIR
OF ELECTRONS .
BRONSTED-LOWRY -- THE SUBSTANCES WHICH HAVE A TENDENCY TO DONATE PROTONS.
WHAT ARE ACIDS ?
WATER IS NEITHER AN ACID NOR A BASE, BUT IN CERTAIN CASES CAN ACT
AS EITHER AN ACID OR A BASE

7. PROPERTIES OF ACIDS
● ACIDS + ACTIVE METALS ------> SALT + H²
● ACID + METAL CARBONATE / BICARBONATE -----> SALT + WATER +
CARBON DIOXIDE
● ACID + BASE -----> SALT + WATER
● ACID + METALLIC OXIDE ( BASIC ) ----> SALT + WATER

8. REMAINS
COLOURLESS IN
ACIDS
ACIDS TURN BLUE
LITMUS TO RED.
IDENTIFICATION OF ACIDS
TASTE METHYL
ORANGE
LITMUS TEST PHENOLPHTHALEIN
ACIDS ARE SOUR
IN TASTE . TURN METHYL
ORANGE TO DARK
ORANGE /RED.
01 03
02 04

9. TYPES OF ACIDS
( STRENGTH ) -
1. STRONG ACID -- COMPLETE IONIZATION TAKES PLACE *EG: HCl , HNO3
2. WEAK ACID -- PARTIAL IONIZATION TAKES PLACE *EG:HNO2 , HCN
(CONCENTRATION) -
1. CONCENTRATED ACID -- ACID> WATER
2. DILUTE ACID -- WATER> ACID GOOD CONDUCTORS OF ELECTRICITY
( SOURCE ) -
1. ORGANIC ACID -- OBTAINED FROM PLANTS AND ANIMALS (WEAK IN
NATURE ) *EG: CH3COOH , HCOOH , H2CO3
2. INORGANIC ACID -- OBTAINED FROM MINERALS
RED ANTS CONTAIN FORMIC ACID WHICH CAN BE USED FOR
MEDICAL TREATMENT.

10. LIST OF IMPORTANT ACIDS ;
1. CH3COOH - ACETIC ACID
2. HCOOH - FORMIC ACID
3. (COOH)2 - OXALIC ACID
4. HNO3 - NITRIC ACID
5. H2SO4 - SULPHURIC ACID
6. HCl - HYDROCHLORIC ACID
7. HCN - HYDROCYANIC ACID
8. HNO2 - NITROUS ACID
9. H2SO3 - SULPHUROUS ACID
10. C4H6O6 - TARTARIC ACID
11. H2CO3 - CARBONIC ACID
1. COOH INDICATES
ORGANIC ACIDS .
2. WHEN AN ACID IS
GREATLY DILUTED IT
CONCENTRATION OF
H+ IONS PER UNIT
VOLUME
INCREASES.

11. ARRHENIUS THEORY -- AN BASE IS A SUBSTANCE THAT DISSOCIATES AND PRODUCES HYDROXIDE ION
(OH-)
LEWIS THEORY -- THE SUBSTANCES OR ELEMENTS WHICH HAVE A TENDENCY TO DONATE ONE LONE PAIR
OF ELECTRONS .
BRONSTED-LOWRY -- THE SUBSTANCES WHICH HAVE A TENDENCY TO ACCEPT PROTONS.
WHAT ARE BASES ?

12. PROPERTIES OF BASES
● BASE + AMPHOTERIC METAL -----> SALT + H²
● BASE + NON METAL OXIDE (ACIDIC)-----> SALT + WATER
● BASE + NON METAL CARBONATE / BICARBONATE -----> NO
REACTION .
AMPHOTERIC METALS -
METALS WHICH PRODUCE HYDROGEN GAS UPON REACTING WITH AN ACID OR A
BASE .
Sb , Zn , Al , Pb , As , Sn ------> these metals are used as anions
1. Sb > SbO3 = -1 { ANTIMI NATE }
2. Zn > ZnO2 = -2 { ZINCATE }
3. Al > AlO2 = -1 { META ALUMINATE }
4. Pb > PbO2 = -2 { PLUMBATE }
5. As > AsO3 = -3 { ARSENATE }
6. Sn > SnO2 = -2 { STANNATE}

13. CHANGES TO PINK
IN BASES.
BASES TURN RED
LITMUS TO BLUE.
IDENTIFICATION OF BASES
TASTE METHYL
ORANGE
LITMUS TEST PHENOLPHTHALEIN
BASES ARE
BITTER IN TASTE . TURN METHYL
ORANGE TO
YELLOW .
01 03
02 04

14. TYPES OF BASES
( STRENGTH ) -
1. STRONG BASE-- COMPLETELY DISSOCIATE IN AN AQUEOUS SOL.
2. WEAK BASE -- PARTIALLY DISSOCIATE IN AN AQUEOUS SOL.
( CONCENTRATION )
1. CONCENTRATED BASE-- BASE > WATER
2. DILUTE BASE-- WATER > BASE

15. BASES
ALKALI
WATER SOLUBLE BASES ARE KNOWN AS ALKALI .
EXAMPLES:
1. NaOH
2. KOH
3. Ca(OH)2
4. NH4OH

16. POINTS TO REMEMBER
● WHEN DILUTING AN ACID ,ALWAYS ADD THE ACID TO THE
WATER USING A BEAKER , WHILE CONSTANTLY STIRRING
THE MIXTURE .
● BASES ARE NOT VERY VIGOROUS WHEN REACTING WITH WATER
AND HENCE CAN BE ADDED IN ANY WAY, EITHER THE WATER TO
THE BASE OR THE BASE TO THE WATER .
** BOARDS Q. !

17. WHY!?
WATER SHOULD NOT BE ADDED TO
CONCENTRATED ACIDS BECAUSE
THIS REACTION IS HIGHLY
EXOTHERMIC IN NATURE AND IF THE
WATER IS DROPPED OVER THE ACID ,
THE HEAT ENERGY RELEASED MAY
CAUSE THE MIXTURE TO SPLASH OUT
AND CAUSE SEVERE BURNS .

18. KEEP IN MIND!
● ALL ALKALI ARE BASES BUT ALL BASES ARE
NOT ALKALI.
IMP.

19. pH SCALE
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20. WHAT IS pH ?
pH
STANDS FOR POWER OF HYDROGEN
POTENTIAL OF
HYDROGEN
A UNIVERSAL INDICATOR HAS A pH RANGE FROM ZERO {0} TO FOURTEEN {14}
THAT INDICATES THE ACIDITY OR BASICITY OF A SOLUTION .
A NEUTRAL SOLUTION HAS A pH OF 7
* pH = - log ₁₀ [H+]
pH is equal to the negative logarithm of concentration of H+ ions while the log
base is 10

21. pH PAPER
POWER AND COLOUR
0-2 --- DARK RED
3-5 --- ORANGE (ish)
6-7 --- PARROT GREEN
7 --- GREEN
8+ --- DARK GREEN

22. FOR PURE WATER :
H+ = OH- = 10 ^-7 mole/litre
# [ value of H+ ions is equal to the
concentration of OH- ions in pure
water ]
* VALUE OF CONCENTRATION =
mole/litre

23. USES OF pH IN
EVERYDAY LIFE
● BLOOD
● TOOTH DECAY
● SOIL
● DIGESTIVE SYSTEM

24. MANUFACTURING OF
ACIDS AND BASES

25. * ACIDS
● NON METAL OXIDE +
WATER → ACID
● HYDROGEN + HALOGENS →
ACID
● METALLIC SALT + con.
H2SO4 → SALT + VOLATILE
ACID

26. * BASES
● METAL + OXYGEN → BASE
● METAL + WATER → BASE + H2
● METALLIC OXIDE + WATER → BASE
● AMMONIA + WATER → AMMONIUM
HYDROXIDE ( BASE )

27. SALTS
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28. WHAT ARE SALTS ?
SALTS ARE A COMBINATION OF THE
ANION OF AN ACID AND THE CATION
OF A BASE .

29. FAMILY OF SALTS
SALTS HAVING THE SAME CATION
OR ANION BELONG TO THE SAME
FAMILY OF SALTS .

30. pH OF
SALTS

31. WHAT DETERMINES THE pH OF SALTS ?
● A SALT OF A STRONG ACID AND A STRONG
BASE WILL BE NEUTRAL . ( pH = 7)
● A SALT OF A STRONG ACID AND WEAK BASE
WILL BE ACIDIC IN NATURE ( pH < 7 )
● A SALT OF A WEAK ACID AND A STRONG
BASE WILL BE BASIC IN NATURE ( pH > 7 )
● FOR A SALT OF A WEAK ACID AND A WEAK
BASE , THE pH IS DETERMINED BY USING THE
pH SCALE.

32. WHEN CO2 IS ADDED TO LIME WATER , IT
WILL TURN MILKY DUE TO THE FORMATION
OF A WHITE PRECIPITATE OF CALCIUM
CARBONATE .
HOWEVER , WHEN EXCESS CO2 IS ADDED
HERE , THE MILKY COLOUR WILL DISAPPEAR
DUE TO THE FORMATION OF CALCIUM
BICARBONATE WHICH IS SOLUBLE IN WATER
.
TESTING OF CARBON DIOXIDE GAS .

33. MANUFACTURING
OF SALTS
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34. COMMON SALT
{NaCl}
COMMON SALT IS FORMED BY THE MIXTURE OF
HYDROCHLORIC ACID AND SODIUM HYDROXIDE
SOLUTION .
- IT IS USED IN FOOD
NaOH + HCl → NaCl + H2O

35. CAUSTIC SODA / sodium hydroxide
{NaOH}
WHEN ELECTRICITY IS PASSED THROUGH AN AQUEOUS
SOLUTION OF SODIUM CHLORIDE ( brine solution ) , THE
SODIUM CHLORIDE DECOMPOSES INTO ITS
COMPONENTS AND FORMS CAUSTIC SODA .
2NaCl + 2H20 -(ELECTRIC CURRENT)→ NaOH + H2 + Cl2

36. BLEACHING POWDER/ calcium hypochlorite
/calcium oxychlorite {CaOCl2}
BLEACHING POWDER IS OBTAINED BY THE ACTION OF
CHLORINE ON DRY SLAKED LIME .
Ca(OH)2+ Cl2 → CaOCl2 + H2O
On standing for a longer time , it undergoes auto-oxidation
which leads to the decrease in the bleaching action of
bleaching powder.

37. USES OF BLEACHING POWDER
1. IT IS USED IN BLEACHING TEXTILES SUCH AS
COTTON AND LINEN IN THE TEXTILE INDUSTRY.
2. IT IS USED AS A DISINFECTANT FOR WATER TO
MAKE IT FREE FROM GERMS .
3. IT IS USED AS AN OXIDISING AGENT IN MANY
CHEMICAL INDUSTRIES .

38. BAKING SODA/sodium bicarbonate {NaHCO3}
*THIS PROCESS IS CALLED SOLVAY PROCESS *
IT IS PRODUCED BY USING SODIUM CHLORIDE ,
WATER , CARBON DIOXIDE AND AMMONIA AS THE RAW
MATERIALS .
NaCl + H2O + CO2 + NH3 → + NH4Cl +
NaHCO3
WHAT HAPPENS WHEN BAKING SODA IS HEATED DURING COOKING ?
→ SODIUM BICARBONATE DECOMPOSES INTO SODIUM CARBONATE ,
WATER AND CARBON DIOXIDE.

39. USES OF BAKING SODA
1 2 3
FOR MAKING BAKING
POWDER , WHICH IS
A MIXTURE OF
BAKING SODA AND
A MILD EDIBLE ACID
SUCH AS TARTARIC
ACID
IT IS AN
INGREDIENT IN
ANTACIDS . BEING
ALKALINE IT
NEUTRALIZES
THE EXCESS ACID
IN THE STOMACH
AND PROVIDES
RELIEF .
IT IS USED IN
SODA - ACID
FIRE
EXTINGUISHERS

40. IMPORTANT
1.
NaHCO3 + H+ → CO2 + H20 + SODIUM SALT OF THE ACID
WHAT HAPPENS WHEN
BAKING POWDER IS
HEATED OR MIXED IN
WATER?
CARBON DIOXIDE PRODUCED IN THIS REACTION CAUSES BREAD OR CAKE
TO RISE , MAKING THEM SOFT AND SPONGY.

41. WASHING SODA/sodium carbonate.decahydrate
{Na2CO3 . 10H2O}
IT IS OBTAINED BY HEATING BAKING SODA AND
RE-CRYSTALLIZING IT.
NaHCO3 → Na2CO3 + H2O
Na2CO3 + 10H2O → Na2CO3.10H2O
SODIUM CARBONATE IS A WHITE CRYSTALLINE SUBSTANCE . ITS
SOLUTION IN WATER IS ALKALINE IN NATURE . ITS MAIN PROPERTY
IS TO REMOVE DIRT/GREASE FROM CLOTH.

42. USES OF WASHING SODA
● IT IS USED IN GLASS , SOAP AND PAPER INDUSTRIES .
● IT IS ALSO USED FOR THE MANUFACTURING OF SODIUM
COMPOUNDS ( INSECTICIDES AND PESTICIDES ) SUCH AS BORAX . IT
ALSO REMOVES PERMANENT HARDNESS OF WATER.
● IT IS USED AS A CLEANSING AGENT IN DETERGENTS AND SOAPS IN
HOUSES .

43. PLASTER OF PARIS /calcium sulphate hemihydrate
{CaSO4 . 1/2H2O}
IT IS OBTAINED BY HEATING GYPSUM AT 100℃ OR
373 K
CaSO4 . 2H2O - HEAT→ CaSO4 . ½ H2O
--WHEN GYPSUM IS HEATED ABOVE 400K , ANHYDROUS POP IS
FORMED ( DEAD - BURNT ) WHICH DOES NOT HAVE THE
PROPERTY OF HARDENING .
-- WHEN POP IS MIXED WITH WATER , IT FORMS GYPSUM , GIVING
A HARD SOLID MASS.

44. USES OF POP
● IT IS USED BY DOCTORS FOR FIXING OF FRACTURES .
● IT IS ALSO USED FOR MAKING DECORATIVE PIECES AND FOR MAKING
DESIGNS ON CEILING .

45. WATER OF
CRYSTALLIZATION
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46. WHAT IS IT?
THE CRYSTALS OF SALT OF SOME COMPOUNDS APPEAR TO
BE DRY ( ANHYDROUS ) BUT ACTUALLY CONTAIN SOME
WATER MOLECULES ATTACHED TO THEM . THESE WATER
MOLECULES CONTAIN ACTUAL WATER WHICH IS KNOWN AS
WATER OF CRYSTALLIZATION AND SUCH SALTS ARE CALLED
HYDRATED SALTS .
CuSO4. 5H2O , CaSO4.2H2O , CaSO4. ½ H2O