Types of acids
1. Strong and weak acids
2.Concentrated and dilute acids
3.Organic and inorganic acids
1.STRONG ACID => Those acids are called strong acids which
dissolve completely in water (aqueous solution) to produce
large amount of hydrogen ions+ (H+).
E.g.- Hcl (hydrochloric acid),
H2SO4 (sulphuric acid),
HNO3 (nitric acid),
HBr (hydrobromic acid).
2.Weak acid=> Those acids are called weak acids which don’t
dissolve completely in water (aqueous solution) to give large
amount of hydrogen ions+ (H+).
E.g.-H2CO3 (carbonic acid),
H3PO4 (phosphoric acid),
CH3COOH (acetic acid)
H3BO3 (boric acid)[ to make antiseptic]
3.Concentrated acids=> when an aqueous solution contains a
large amount of acid in it, then it is called concentrated acid.
4.Dilute acids=> when an aqueous solution contains a less
amount of acid in it, then it is called dilute acid.
✓ Dilution of acid :- The process of mixing concentrated
acid with water to make it dilute is called dilution of
acid.
✓ Note:- Dilution of acid should be done by adding C.A
with water not by adding water with C.A.
(because it is an exothermic reaction and produce a
large amount of heat which can break the glass or
splash to burn or face )
:-less than 1% concentrated HCl is present in human
stomach
:-approx 5% concentrated CH3COOH is present in
vinegar.
5.organic acids=> Those acids which are obtained
from living things(plants and animals) are called
organic acid.
➢ E.g.- citric acid (lemon and
orange)
➢ Lactic acid (milk and curd)
➢ tartaric acid (tamarind and
grapes)
➢ Oxalic acid (tomatoes)
➢ Formic or Methanoic acid or
HCOOH
ant sting and nettle leaf sting)
➢ Acetic or ethanoic acid (vinegar)
➢ Malic acid (apples)
➢ Amino acid (proteins)
➢ Ascorbic acid (vitamin c).
6.Inorganic acids=> Those acids which are obtained from
minerals are called inorganic acids.
➢ E.g. H2SO4 (sulphuric acid)
➢ HCl (hydrochloric acid)
➢ HNO3 (nitric acid)
➢ H2CO3 (carbonic acid).
Note:- Basicity of acid=> Number of ionisable hydrogen ions
(H+) present in one molecules of acid is called its basicity.
➢ H2SO4
basicity=2 (monobasic)
➢ HCL
basicity=1(monobasic)
➢ HNO3
Basicity=1(monobasic)
➢ H2SO4
Basicity=2(monobasic)
➢ H2CO3
Basicity=2(monobasic)
➢ H3PO4
Basicity=3(tribasic)
➢ CH3COOH
Basicity=1(monobasic)
➢ HCOOH
Basicity=1(monobasic)
Formation of acids
✓ Acids are formed by the:1. Reaction of non-metals with hydrogen
➢
➢
Cl2 + H2
Br2 + H2
HCl
HBr
2.Reaction of non-metal oxide with water:➢
➢
➢
CO2 + H2O
SO3 + H2O
NO2 + H2O
H2CO3
H2SO4
HNO3.
INDICTORS
:- Indicators are those substances which change their colours
when put into acid or base to show whether the given
substance is base or acid.
Indicator
1 litmus
paper/soln[obtained from
lichen plant of thallophyta
group]
2 Methyl orange
3 Phenolphthalein
4 Turmeric
5 Beetroot
6 Red cabbage leaves
Colour in acid
Red
Red
Colourless
Yellow
Red-purple
Red-purple
Colour in base
Blue
Yellow
Pink
Reddish-brown
Yellow
Green
➢ Olfactory indicators :- Those substances which change
their smell in acidic or basic solution is called olfactory
indicators.
E.g- onion, clove oil, vanilla essence.
➢ Universal indicator:- Universal indicator is a mixture of
different indicators() which shows the strength of acids
and bases with the help of a pH scale.