Suppose you are asked to prepare 100 mL 1.0M solution of oxalic acid. As a first step you have to calculate the mass of oxalic acid required for preparing 100 mL of solution.
Molar mass of oxalic acid = 126 g
126 g of oxalic acid is required to prepare 1 litre solution of molarity 1 M.
To prepare 0.1 Molar 100 mL solution, you dissolve 1.26 g of the oxalic acid in distilled water and make it up to 100 mL.
Similarly, to prepare 0.1 M solution of ferrous ammonium sulphate, 3.92 grams of ferrous ammonium sulphate is dissolved in distilled water so as to get 100 mL solution.
How To Perform Experiment
To Prepare standard solutions of oxalic acid and ferrous ammonium sulphate, the following steps are followed:
- Weigh the required amount of substance using an analytical balance. The substance should be weighed in a weighing bottle.
- Transfer the weighed substance into a standard flask (100 mL) and dissolve in minimum amount of distilled water.
- Make the volume of solution up to the mark in the standard flask. Shake it by tilting the flask upside down.
- In case of ferrous ammonium sulphate, before making the solution up to the mark, dilute sulphuric acid (15 mL) should be added to prevent the hydrolysis.