Salt Preparation is a topic that quite a few students are weak in. In order to successfully attempt any question on salt preparation, one has to be familiar with the following:-
- Solubility table
- Methods of preparation
In general, when one is posed with a salt preparation question, he needs to have the following train of thought:
- Is the salt soluble? (knowledge of solubility table)
- If soluble –> is it a SPA/Group I salt? If yes –> acid/alkali titration; if NO –> acid + excess method.
If not soluble –> ionic precipitation method
Let’s take a quick look at how we can apply this knowledge to answering questions.
Briefly describe how sodium sulfate can be prepared in the lab.
- Is the salt soluble? (Yes! All Sodium Potassium and Ammonium salts are soluble!)
- Is it a SPA salt? (Yes!)
- Acid + alkali titration.
- We will use sulfuric acid because we wish to obtain a sulfate salt. (We use HCl if we want to get a chloride salt and HNO3 if we want to get a nitrate salt.)
We will use sodium hydroxide as the alkali.
- Briefly describe the titration method!
I hope this short post has helped you clear some doubts about salt preparation. If you found it useful, feel free to share this with your friends!