Question

What are the uses of \[potash{\text{ }}alum\]?
a.Purification of impure water
b.Used for catalysis
c.Used for stopping bleeding
d.Used in dyeing industry

Answer 1

Hint: We all have used or heard the name ‘fitkari’ .It is nothing but \[potash{\text{ }}alum\]. Try to recall its uses. It has many uses which include medicinal as well as industrial uses as well. It is also known by the name \[potassium{\text{ }}alum\]

Complete Answer:
\[potassium{\text{ }}alum\] or \[potash{\text{ }}alum\] is a hydrated \[potassium{\text{ }}aluminium{\text{ }}sulfate\] and has a chemical formula \[KAl{(S{O_4})_2}.12{H_2}O\] . it exists in different forms, like crystalline form or in powder form. It has many uses, like the powder form is sold with kitchen spices or pickling ingredients. It is also sold as a deodorant rock.
There are different types of alum like \[potassium{\text{ }}alum\] , \[selenium{\text{ }}alum\], soda alum, chrome alum, \[ammonium{\text{ }}alum\] etc. they are used in different form like in an antiseptic, as an acidulant. Most common form of alum is \[potassium{\text{ }}alum\]. It is available at grocery stores. It is widely used for water purification treatment as it enhances the sedimentation process, thus making the drinking water pure. Chrome alum has a violet colour and is used as dye as it gives violet colour to other alum. \[selenium{\text{ }}alum\] is used as an antiseptic due to its potent oxidising agent.
Thus we can say that an alum is used for purification of impure water, as an antiseptic as well as as a dyeing agent.

Therefore options a, c and d are correct.

Note:
\[potash{\text{ }}alum\] has many other uses as well apart from mordant for the dyeing industry and the uses mentioned above. It is used in leather tanning, aftershave treatment, fireproof textiles and baking powder. It is drawn from alumnite minerals.