Common Acid-Base Indicators Family of Salt
Indicator pH range Acid Base Salts having common acidic or basic
Thymol Blue 1.2-2.8 red yellow radicals are said to belong to same family.
Methyl yellow 2.9-4.0 red yellow
Methyl orange 3.1-4.4 red orange Sodium chloride (NaCl) and Calcium
Bromphenol 3.0-4.6 yellow blue-violet chloride (CaCl2) belong to chloride family.
blue Calcium chloride (CaCl2) and calcium
Methyl red 4.4-6.2 red yellow sulphate (CaSO4) belong to calcium
Phenol red 6.4-8.0 yellow red family.
Neutral red 6.8-8.0 red yellow
Phenolphthalein 8.0-10.0 colorless red Zinc chloride (ZnCl2) and Zinc sulphate
Nile blue 10.1-11.1 blue red (ZnSO4) belong to zinc family.
Nitramine 11.0-13.0 colorless orange red
Characteristics of salt
Litmus Paper or Solution 1. Most of the salts are crystalline solid
2. Salts may be transparent or opaque
This indicator is present in two colors: red 3. Most of the salts are soluble in water
and blue. 4. Solution of salts conducts electricity. Salts
Blue litmus paper or solution is used to conduct electricity in their molten state
test a substance for acidity. also
5. The salt may be salty, sour, sweet, bitter
Red litmus paper or solution is used to test
and umami (savoury)
a substance for alkalinity. 6. Neutral salts are odourless
Indicates Litmus Litmus
Paper turns Solution turns Acidic, Basic and Neutral Salts
In Acid red red
In Base blue blue Acidic salt: Salts which are formed after the
In Neutral Color does purple reaction between a strong acid and weak base
not change are called acidic salt. The pH value of acidic
salt is lower than 7. e.g. ammonium sulphate,
ammonium chloride, etc.
Basic Salt: Salts which are formed after the
Salts are the ionic compounds which are
reaction between weak acid and strong base
produced after the neutralization reaction
are called basic salt. The pH value of a basic
between acid and base.
salt is more than 7. e.g. sodium carbonate,
Salts are electrically neutral. sodium acetate, etc.
Sodium chloride (NaCl) is also known as table Neutral Salt: Salts produced because of
salt or common salt. reaction between strong acid and strong base
are neutral in nature. The pH of value of such
salts is equal to 7, i.e. neutral. e.g. Sodium
chloride, sodium sulphate, potassium chloride,