Submission of Proposal under Star College Scheme

) Determining the amount of primary standards to be weighed:
From the chart, note the weight of the substance to be weighed & the final volume to which it is to be diluted.
b) Weighing on watch glass :

1. 
   Watch glass should be thoroughly dry (both the sides):
   
2. 
   Do not weigh on paper (use only watch glass)
   
3. 
   Filter paper will absorb the mixture. Solid particles may get attached to the filter paper.
   
4. 
   Watch glass should be covered with 'dry funnel. (Collect the substance in the centre of the watch glass).
   
5. 
   While recording the final reading doors of the balance should be closed. Record the weight in the rough journal and not on a paper or hand.
   
6. 
   Maintain the balance and balance room clean.
   

c) Transferring substance in a beaker:
Transfer the substance in breaker with jet of water from wash bottle
taking care that all the solid particles is transferred in the beaker. Then, wash watch glass with minium amount of water with washings transfered in the beaker
d) Dissolving the solute completely by stirring with glass rod:
e)Transferring in a standard measuring flask through funnel :
Transfer the clean solution through funnel with the help of glass rod in to the standard flask. Wash the beaker 2-3 times using 5-10cm3 of water each time. Wash glass rod & then funnel & All these washings must be transferred in the standard flask.
f) Diluting to final volume:
Add water directly up to 2 cm3 less than marking and then the final dilution should be done drop wise with the help of the glass dropper. Lower meniscus should tocuh the marking on the standard flask.


4. Volumetric titration:
Check, the burette should not leak.
Burette: Wash, rinse & before adjusting zero marking on the burette, make sure that there is no air bubble. Lower meniscus should touch the zero marking on the burette. Pipette: Wash, rinse & pipette out the solution with dry index finger kept on the pipette. Transfer the solution from the pipette to the flask without blowing the pipette. indicator: Add constant amount of indicator for each titration (2-3 drops). Observe the colour change on the background of clean white tile. Before starting the titration, remove the funnel.
5. Errors &Accuracy:
Observe all the precautions explained in the earlier part to ensure that there are no procedural errors and that will ensure the accuracy. Report the constant burette reading,