A student dissolved 30 mg of a crude unknown in 2 ml of 95% ethanol at room temperature. After chilling in an ice bath and washing crystal with small amount of ice-cold ethanol, she recovered 5mg. Why was the recovery so low?

2 answers

1) solubility in cold ethanol is higher than expected.
A. Too soluble in ethanol.
B. The sample was VERY crude (not much of the compound to start with).