Below is the method for a practical to do this but there are a few things I dont understand, please help!
I have put my questions into the method in capital letters)
• Add the drying agent to a conical flask containing an organic solvent (CAN ANYONE SUGGEST A SUITABLE DRYING AGENT AND ORGANIC SOLVENT TO USE IT ON?)
• With a spatula add the drying agents in small amounts and swirl the flask.
• At first the drying agent will stick to the side of the flask and form lumps.
• As more is added it will form a free flowing powder in the liquid.
• At this point the liquid will appear clear and no further drying agent should be added.
• The liquid is then gravity filtered, using a funnel and filter paper.
• Any drying agent remaining in the flask should be washed with a small amount of pure dry solvent (WHATS THIS MEAN? DO I POUR THIS pure dry solvent INTO THE FLASK WITH THE ORGANIC SOLVENT I HAVE JUST FILTERED?) as should any solid remaining in the filter paper (DO I JUST POUR PURE DRY SOLVENT INTO THE FILTER PAPER, DO I NEED THE STUFF IN IT?).
Thanks for any help offered
M
I have put my questions into the method in capital letters)
• Add the drying agent to a conical flask containing an organic solvent (CAN ANYONE SUGGEST A SUITABLE DRYING AGENT AND ORGANIC SOLVENT TO USE IT ON?)
• With a spatula add the drying agents in small amounts and swirl the flask.
• At first the drying agent will stick to the side of the flask and form lumps.
• As more is added it will form a free flowing powder in the liquid.
• At this point the liquid will appear clear and no further drying agent should be added.
• The liquid is then gravity filtered, using a funnel and filter paper.
• Any drying agent remaining in the flask should be washed with a small amount of pure dry solvent (WHATS THIS MEAN? DO I POUR THIS pure dry solvent INTO THE FLASK WITH THE ORGANIC SOLVENT I HAVE JUST FILTERED?) as should any solid remaining in the filter paper (DO I JUST POUR PURE DRY SOLVENT INTO THE FILTER PAPER, DO I NEED THE STUFF IN IT?).
Thanks for any help offered
M
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I would normally suggest sodium or calcium hydride as drying agents, but in this particular method, they would be very dangerous. Anhydrous magnesium sulphate is much safer and just as effective for this procedure. So use MgSO4.
For washing the drying agent, you add a little bit of the dry solvent to the flask used for drying, just like you mentioned. Pour this into the filter, and try to get as much of the drying agent into the filter as you can. To finish off, take some more of the dry solvent and just add it to the filter paper containing the drying agent, and let the solvent run off. This is all that "washing" means in this procedure.
For washing the drying agent, you add a little bit of the dry solvent to the flask used for drying, just like you mentioned. Pour this into the filter, and try to get as much of the drying agent into the filter as you can. To finish off, take some more of the dry solvent and just add it to the filter paper containing the drying agent, and let the solvent run off. This is all that "washing" means in this procedure.