The Given Solution has been Prepared by Dissolving 1.6 g of an Alkali metal Permanganate per litre of Solution

The Given Solution has been Prepared by Dissolving 1.6 g of an Alkali metal Permanganate per litre of Solution. Determine Volumetrically the Atomic mass of the Alkali metal. Prepare M/20 Mohr’s salt Solution for Titration

Chemical Equations
Molecular equations. Let A represent the alkali metal and AMnO₄ represent alkali metal permanganate,

Indicator
AMnO₄ will act as a self-indicator.

End Point
Colourless to permanent pink colour (AMnO₄ in burette).

Procedure

1. Weigh exactly 4.90 g of Mohr’s salt on a watch glass and dissolve in water to prepare exactly 250 ml of its solution using a 250 ml measured flask. Rinse the pipette with
   the M/20 Mohr’s salt solution and pipette out 20.0 ml of it in a washed titration flask.
2. Rinse and fill the burette with the given AMnO₄ solution.
3. Add one test-tube (~ 20 ml) full of dilute sulphuric acid (~ 4M) to the solution in titration flask.
4. Note the initial reading of the burette.
5. Now add AMn04 solution from the burette till a permanent light pink colour is just imparted to the solution in the titration flask.
6. Note the final reading of the burette.
7. Repeat the above steps 4-5 times to get a set of three concordant readings.

Observations
Weight of watch glass =……. g
Weight of watch glass + Mohr’s salt =…………..g
Weight of Mohr’s salt = 4.90 g
Volume of solution prepared = 250 ml
Molarity of Mohr’s salt solution = M/20
Volume of Mohr’s salt solution taken for each titration = 20.0 ml

Calculations
Prom the balanced chemical equation, it can be seen that 2 moles of AMnO₄ react with 10 moles of Mohr’s salt.

Chemistry Lab ManualNCERT Solutions Class 12 Chemistry Sample Papers

The post The Given Solution has been Prepared by Dissolving 1.6 g of an Alkali metal Permanganate per litre of Solution appeared first on Learn CBSE.