ICSE Class 7 Answered
what are basic salts?
what are indicators?
what are acid base indicators?
what is basicity of an acid?
what is acidity of an base?
1) The salts formed by the partial replacement of the hydroxyl group of a di- or tri- acidic base by an acidic radical.
Example:
Mg (OH) 2 + HCl Mg (OH) Cl + H2O
2) They are complex substances that acquire separate colours in acidic and basic media.
Example:
Litmus, methyl orange, phenolphthalein etc.
Examples of acid-base indicators are as follows:
Methyl orange, phenolphthalein, turmeric juice, red-cabbage juice etc.
4) The number of replaceable hydronium ions (H3O+) in an acid is called basicity of an acid.
Or
The number of hydronium ions (H3O+) that can be produced by the ionisation of one molecule of that acid in aqueous solution.
5) The number of replaceable hydroxyl (OH-) Ions in a base is called the acidity of that base.
Or
The number of hydroxyl ions (OH-) that can be produced by the ionisation of one molecule of that base in aqueous solution.