THIS PRESENTATION IS FOR THE STUDENTS STUDYING IN SENIOR CLASSES .IT WILL HELP THE CHILD TO RECALL THE CONTENT IN SHORT TIME IT WILL HELP TO BUILD THE STRONG AND CLEAR CONCEPT KNOWLEDGE.

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

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

3.  Acids produce H+ ions when dissolved in water. H+
ions cannot exist alone . So they combine with
water molecule (H2O) to form H3O+ (hydronium
ions).For eg
 HX (acid) + H2O → H3O+ + X–
 Hydrochloric acid (HCl) gives hydrogen ion
(H+) and chloride ion (Cl–) when it is
dissolved in water.
HCl + H2O → H3O+ + Cl-

4.  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-
 Carbonic acid (H2CO3) gives hydrogen ion (H+) and
carbonate ion (CO3
2-) when it is dissolved in water.
H2CO3 + H2O → H3O+ + CO3
2-

5.  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.  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+).
 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–
 Acids conducts electricity as they produce ions in aqueous solution.
 Decrease in H30+ ions concentration per unit volume results in formation
of dilute acids.

7.  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.

8.  Bases are the substances which give give hydroxide
ions (OH–) in aqueous solution.
 Bases are also defined as the oxides or hydroxides
of metals or an aqueous solution of ammonia which
reacts with H+ or H3O+ ion of an acid to form salt
and water
 They are bitter in taste, have soapy touch, turn red
litmus blue

9.  Sodium hydroxide (caustic soda) – NaOH
 Calcium hydroxide – Ca(OH)2
 Potassium hydroxide (caustic potash) – (KOH)
 Magnesium hydroxide – Mg(OH)2
 Ammonia solution- NH4OH

10.  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)

11.  An Alkali is defined as the hydroxide of alkali metal or
alkaline earth metal whereas base is a substance which give
OH- ion an aqueous solution.
 All bases do not dissolve in water. An alkali is a base that
dissolves in water. Commonly used alkalies are:
 NaOH -Sodium hydroxide
 KOH - Potassium hydroxide
 Ca(OH)2 -Calcium hydroxide
 Note : All alkalies are bases but all bases are not alkalies.
 Exception: NH4OH (Ammonium hydroxide) is a base which is
soluble in water.

12.  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.

13.  The process of dissolving an acid, specially nitric
acid or sulfuric acid or a base in water is a highly
exothermic one. As a rule: Always add acid to water
and never the other way! The acid must be added
slowly to water with constant stirring. If one mixes
the other way by adding water to a concentrated
acid, the heat generated causes the mixture to
splash out and cause burns.

15.  Acids react with active metals to
give salt and hydrogen gas.
Metal + acid → salt + hydrogen gas
 Zn + H2SO4→ZnSO4 + H2

16.  Magnesium + Hydrochloric acid →Magnesium chloride +Hydrogen gas
 Zn (s) + H2SO4(dil) →ZnSO4(aq) + H2(g)
 Aluminum + Sulphuric acid → Aluminum sulphate +Hydrogen gas
 2Al (s) + 3H2SO4(dil) →Al(SO4)3 (aq) + 3H2(g)
 Iron + Hydrochloric acid → Iron chloride +Hydrogen
 Fe + 2HCl →FeCl2 + H2
 Dilute hydrochloric acid reacts with magnesium ribbon.
 Mg (s) + 2HCl(dil) →MgCl2(aq) + H2(g)
 Reaction of nitric acid with zinc granules
2HNO3+Zn−→Zn(NO3)2+H2
 Reaction of Acetic acid with zinc granules
2CH3COOH+Zn→(CH3COO)2Zn + H2

18.  The gas evolved after reaction of acid
with metal can be tested by bringing a
lighted candle near it. If the gas bums
with a pop sound, then it confirms the
evolution of hydrogen gas. Burning
with pop sound is the characteristic
test for hydrogen gas.

19.  Acids react with metal carbonate and metal
hydrogen carbonate to give carbon dioxide.
 Acid + metal carbonate → salt+ water + CO2
 Acid + metal bicarbonate → salt+ water + CO2
 Na2CO3 + 2HCl → 2NaCl + H2O + CO2
 NaHCO3 +HCl → NaCl + H2O + CO2
 Na2CO3 + H2SO4→ Na2SO4 + H2O + CO2
 2NaHCO3 + H2SO4→ Na2SO4 + 2H2O + CO2

20.  The gas evolved because of reaction of the acid with metal
carbonate or metal hydrogen carbonate turns lime water milky.
This shows that the gas is carbon dioxide gas. This happens
because of the formation of a white precipitate of calcium
carbonate.
 NaHCO3 +HCl → NaCl + H2O(l) + CO2 (g)
X Y
 Ca(OH)2 (aq) + CO2(g) → CaCO3(s) + H2O(l)
lime water white ppt(Z)
 Carbon dioxide turns lime water milky when passed through it.
Lime water test is the characteristic test for the detection of
carbon dioxide gas.

21.  But when excess of carbon dioxide is passed through
lime water, it makes milky colour of lime water
disappear. This happens because of formation of
calcium hydrogen carbonate. As calcium hydrogen
carbonate is soluble in water, thus, the milky colour
of solution mixture disappears.
 Ca(OH)2 (aq) + CO2(g) → CaCO3(s) + H2O(l)
 lime water white ppt(Z)
 CaCO3(s) + H2O(l) + CO2(g) →Ca(HCO3 )2(aq)
(soluble )

22.  Acids react with bases to give salt and water.
This reaction is called as neutralization
reaction.
Acid + base → salt + water
 HCl + NaOH → NaCl (salt) +H2O
 KOH +HCl → KCl +H2O
 Ca(OH)2 + 2HCl → CaCl2 + 2H2 O
 Fe(OH)2 + 2HCl → FeCl2 + 2H2 O

23.  Acids react with metals oxides to
give salt and water.
 Acid +Metal oxide → salt + water
 CuO + H2SO4 → CuSO4 + H2O

24.  Calcium is a metal, thus, calcium oxide is a metallic oxide
which is basic in nature. When an acid, such as hydrochloric
acid, reacts with calcium oxide, neutralization reaction takes
place and calcium chloride, along with water is formed.
2HCl + CaO → CaCl2 + H2O
H2SO4 + CaO → CaSO4 + H2O
Similarly, when sulphuric acid reacts with zinc oxide, zinc
sulphate and water are formed
 2HCl + ZnO → ZnCl2 + H2O
H2SO4 + ZnO → ZnSO4 + H2O
 Copper oxide reacts with Hydrochloric acid to form Copper
Chloride and Water
 CuO+HCl→CuCl2+H2O

26.  REACTION OF BASE WITH METALS
 Certain reactive metals such as Zinc,
Aluminium, and Tin react with alkali
solutions on heating and hydrogen gas is
evolved.
 Base + metal → oxysalt + hydrogen gas
 2NaOH + Zn → Na2ZnO2 +H2
sodium meta-aluminate
 2NaOH + 2Al+2H2O→ 2NaAlO2 +3H2
sodium zincate

27. Bases react with acids to form salt
and water.
Base + acid → salt + water
KOH +HCl → KCl +H2O

28. These oxides are generally acidic in
nature. They react with bases to form salt
and water.
Base + CO2 →Salt +water
2NaOH + CO2 → Na2CO3 + H2O

29.  Potassium hydroxide gives Potassium carbonate and
water when it reacts with carbon dioxide.
2KOH + CO2 → K2CO3 + H2O
Calcium hydroxide gives calcium carbonate and water
when it reacts with carbon dioxide.
Ca(OH)2 + CO2 → CaCO3 + H2O

30.  When bases are warmed with an ammonium
salt, ammonia gas is produced.
e.g. NH4Cl + NaOH → NaCl + H2O + NH3

31.  All bases except NaOH decompose on
heating to give oxides.
Ca(OH)2 +Heat→ CaO + H2 O
2Al(OH)3 + Heat → Al2O3 + 3H2 O

32. ◦ When added to the solutions of the salts of the heavy
metals viz. copper, iron, zinc, etc. the bases produce
insoluble metal hydroxides as precipitates.
CuSO4(aq) + 2NH4OH → (NH4)2SO4 + Cu(OH)2↓ (pale blue)
ZnSO4(aq) + 2NaOH(aq) → Na2SO4(aq) + Zn(OH)2 ↓ (white)

33. ◦The hydroxides of zinc, aluminium and lead are
amphoteric i.e. they can act as weak bases as well as
weak acids.
As weak bases :
Zn(OH)2 + 2HCl (dil) → ZnCl2(aq) + 2H2O
Al(OH3)(s) + 3HCl(dil) → AlCl3(aq) + 3H2O
As weak acids
Al(OH3)(s) + 2NaOH(aq) → NaAlO2(aq) + 2H2O
Sodium metaaluminate
Zn(OH)2(s) + 2NaOH (aq) → Na2ZnO2(aq) + 2H2O
Sodiumzincate

34.  Bases donot react with metal
carbonates and metal hydrogen
carbonates as both are basic in
nature.

35. THANKS