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Unformatted text preview: The best way to deal with these problems is to
slow things down.
Using dilute, warm solutions during
precipitation gives counter ions time to leave
and helps break up pockets.
Digestion and aging the precipitate provides
additional times for this to occur as well. When a precipitation reagent is added as a
solution to our analyte there will always be
locally high concentrations.
This is responsible for many of our problems
regardless of how slowly we add the reagent or
how fast we stir.
Precipitation from homogeneous solution is an
an approach that can avoid this problem. After filtration, the precipitate must be dried to
Removes excess solvent
Drives off any volatile species.
In some cases, the precipitate is heated to a point
where it decomposes to a stable form for
Thermobalances can be used to determine
optimum drying time and temperatures. ...
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This note was uploaded on 01/07/2012 for the course CHEM 290 taught by Professor Harvey during the Fall '08 term at SUNY Stony Brook.
- Fall '08