In order to obtain pure synthetic plant hormone, a 2:1 mixture of water and

ethanol is used as the crystallizing solvent. Why is a solvent mixture used?
A. Organic compounds are not soluble in pure ethanol.
B. Ethanol and water have similar boiling points, so concentration is easy.
C. Salts and inorganic impurities are soluble in pure water.
D. Synthetic plant hormone dissolves in the water/ethanol mixture at low
temperatures.
E. None of the above.

Any ideas?

I thought it was A

To determine why a solvent mixture is used to obtain pure synthetic plant hormone, let's analyze each option:

A. Organic compounds are not soluble in pure ethanol.
This statement is generally inaccurate. Many organic compounds are soluble in pure ethanol. However, there may be specific organic compounds that are not soluble in ethanol alone. Therefore, this option is not a valid reason for using a solvent mixture.

B. Ethanol and water have similar boiling points, so concentration is easy.
While it is true that ethanol and water have similar boiling points (ethanol: 78.4°C, water: 100°C), the boiling point similarity does not directly address why a solvent mixture is used for crystallization. Concentration can be achieved by evaporating the solvent, regardless of its composition. Therefore, this option is not a valid reason for using a solvent mixture.

C. Salts and inorganic impurities are soluble in pure water.
This statement is accurate. Salts and inorganic impurities generally dissolve readily in water. Therefore, using a mixture of water and ethanol as the crystallizing solvent helps prevent the inclusion of salts and inorganic impurities in the crystals during the crystallization process. This option provides a valid reason for using a solvent mixture.

D. Synthetic plant hormone dissolves in the water/ethanol mixture at low temperatures.
There is no information given in the question about the solubility of the synthetic plant hormone in the solvent mixture at low temperatures. Without this information, we cannot determine if this option is a valid reason for using a solvent mixture.

E. None of the above.
Based on our analysis, option C seems to be the most reasonable choice as a valid reason for using a solvent mixture. However, without additional information, we cannot definitively determine the correct answer. It's always important to consider the specific properties of the compounds involved and the desired outcome of the crystallization process in order to determine the most suitable solvent mixture.