1) A student recrystallizes 1.00 g of the unknown compound from 50 mL of water. After...

1) A student recrystallizes 1.00 g of the unknown compound from 50 mL of water. After allowing the mixture to cool to room temperature (25 °C), the student collects the recrystallized compound using vacuum filtration. What is the theoretical maximum percent recovery of the unknown compound for this recrystallization step?

2)A student recrystallizes 1.00 g of the unknown compound from 50 mL of water. After allowing the mixture to cool in an ice bath (0 °C), the student collects the recrystallized compound using vacuum filtration. What is the theoretical maximum percent recovery of the unknown for this recrystallization step?

Expert Solution

Below two reasons for loss of compounds

1) In the filtration step, material was lost on filter paper: this is common at 25 ^o C and 0 ^o C

2) Material did not completely crystallize from solution: The percentage recovery depends on the final temperature of the solution after recrystallization, as at 0 ^o C the solute will most likely be less soluble than at room temperature

% of recovery = (amount pure product recovered/amount crude product used) X100

If you know the solubility of your unknown compound in water then we can calculate the exact % of recovery.

You will get maximum recovery filtration at 0 ^o C than room temperature filtration

queen_honey_blossom answered 2 years ago

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