A good method to separate alum (phitkari) from impure samples is:
A good method to separate alum (phitkari) from impure samples is:
The correct option is C Crystallization
Crystallisation is a good method to get a pure sample from solutions.
To understand how this works, let's take salt and water. We can add salt in water and we know that it dissolves. But do you know that there is a limit? A given quanitity of water can only dissolve a limited amount of salt. The rest of the salt just won't mix.
But interestingly, if we increase the temperature we can increase the amount of salt that dissolves. So if we just heat water, it will dissolve more salt. If we keep increasing the temperature, more and more salt will dissolve. Now, if we just let this hot salt-water solution cool down from a high temperature what would happen? Since amount of salt dissolved depends on temperature, salt will slowly come out of the solution and start depositing. This is what we call crystallisation.
The same techinque can be used to separate alum from impure samples. All we have to do is dissolve alum mixture in water, separate the alum-water solution and heat it. Once it cools down, we will get pure alum.
Crystallization
Crystallisation is a good method to get a pure sample from solutions.
To understand how this works, let's take salt and water. We can add salt in water and we know that it dissolves. But do you know that there is a limit? A given quanitity of water can only dissolve a limited amount of salt. The rest of the salt just won't mix.
But interestingly, if we increase the temperature we can increase the amount of salt that dissolves. So if we just heat water, it will dissolve more salt. If we keep increasing the temperature, more and more salt will dissolve. Now, if we just let this hot salt-water solution cool down from a high temperature what would happen? Since amount of salt dissolved depends on temperature, salt will slowly come out of the solution and start depositing. This is what we call crystallisation.
The same techinque can be used to separate alum from impure samples. All we have to do is dissolve alum mixture in water, separate the alum-water solution and heat it. Once it cools down, we will get pure alum.
