Purpose: To purify a sample of phthalic acid and a sample of “cream
of tartar” by crystallization and determine the recent recovery for each
process.
1-28-99
Procedure
& apparatus:
1. In a 13x100 test tube, the phthalic acid was dissolved in a minimum of hot water.
2. Because there was no observable solid, the sample was not filtered.
3. The solution was allowed to cool slowly to room temperature by removing the test tube from the bath.
4. The solution / solid was cooled to 1°C with an ice bath.
5. The solid was
removed from the mother liqueurs by filtration through a Hirsch Funnel. The solid was rinsed with 1 drop of cold
water.
6. The solid was allowed to dry overnight.
7. The melting point of the product was consistant with the melting point of pure phthalic acid.
Data:
Phthallic
acid (A) potassium hydrogentartrate (B)
mp: 205°C mp:
FW
166.13 g/mol FW
Phthallic
acid used: g potassium
hydrogentartrate used: g
Phthallic
acid recovered: g
Calculations:
.
% Recovery:
Discussion and Errors:
My results are good because.
An error
that
Modifications:
Instead
of
Conclusion: