Hi I'm a bit confused about crystallization. So the compound is varied and we want to extract most of it (via crystallization) at lower/room temps so it should be insoluble at room temperature. But why exactly is it highly soluble at higher temperatures?
In a crystallization procedure, ideal solvent is one in which the target compound is:
A. partially soluble at the boiling point of the solvent, and partially soluble at room temperature.
B. slightly soluble at the boiling point of the solvent, but highly soluble at room temperature.
C. highly soluble at the boiling point of the solvent, but mostly insoluble at room temperature.
C is the best answer. The solubility of a compound in a solvent varies with temperature. Because of this, the temperature of the solution is varied over the course of a crystallization procedure. The ideal solvent for crystallizing a compound requires minimal solvent volume at high temperature, so that most of the compound can be removed in the end. This results from a high degree of solubility in the solvent at high temperatures (such as the boiling point of the solvent). To minimize loss of the target compound, it should precipitate completely at low temperature. This is best explained by choice C; more compound crystallizes out at the lower temperatures, using minimal solvent. The best answer is C.
In a crystallization procedure, ideal solvent is one in which the target compound is:
A. partially soluble at the boiling point of the solvent, and partially soluble at room temperature.
B. slightly soluble at the boiling point of the solvent, but highly soluble at room temperature.
C. highly soluble at the boiling point of the solvent, but mostly insoluble at room temperature.
C is the best answer. The solubility of a compound in a solvent varies with temperature. Because of this, the temperature of the solution is varied over the course of a crystallization procedure. The ideal solvent for crystallizing a compound requires minimal solvent volume at high temperature, so that most of the compound can be removed in the end. This results from a high degree of solubility in the solvent at high temperatures (such as the boiling point of the solvent). To minimize loss of the target compound, it should precipitate completely at low temperature. This is best explained by choice C; more compound crystallizes out at the lower temperatures, using minimal solvent. The best answer is C.
