Submission of Proposal under Star College Scheme

Aim:
To analyse the given sample of limestone for it’s loss on ignition


Theory:
Limestone mainly contains CaCO₃ besides small amount of silica, Fe, Al, Ti etc. The loss on ignition i.e. loss in weight due to loss of CO₂ can be determined by heating a known quantity of the ore in a muffle furnace at about 1000⁰C for about 90 minutes to constant weight.


CaCO₃ CaO +₂ CO


Procedure:

1. 
   Dry the limestone ore in an oven by heating it at 110⁰C for about 60 minutes.
   
2. 
   Weight accurately one g of the dried sample in a previously weighted silica crucible.
   
3. 
   Heat the crucible and it’s contents slowly on a burner for about 30 minutes.
   
4. 
   Transfer the hot crucible along with it’s contents to a muffle furnace and heat it for about 60 minutes.
   
5. 
   Remove and cool crucible. Then weigh. Continue the heating and cooling procedure till constant weight is obtained.
   
6. 
   As CaO residue is hygroscopic in nature, for cooling each time the crucible should be transferred to a desiccators. This weight can be used for calculating loss on ignition.
   

Project: 3
Aim:
To determine the amount of calcium present in the given Sample. (Ostocalcium)


Requirements:
EDTA, 2N HCl, Ammonia buffer, Mordant black –II indicator.


Procedure:

1. 
   Prepare 0.1 M EDTA solution (Dissolve 3.725 g EDTA in 100 cm³ of standard flask, with distilled water)
   
2. 
   Weigh accurately 0.400 g of sample (ostocalcium)& transfer it to a 250 cm³ conical flask.
   
3. 
   Add 15 cm³ of dil. HCl and 100 cm³ of distilled water stir the solution to dissolve the sample completely.
   
4. 
   Add 15 cm³ of ammonia buffer and 5-6 drops of mordant black-II solution as indicator.
   
5. 
   Titrate immediately with 0.1 M EDTA till colour changes sharply from pink to permanent blue.
   

Calculation:

Where, = Molarity of EDTA
= Volume of 0.1 M EDTA
= Weight of the sample