Anonymous asked in Science & MathematicsChemistry · 1 year ago

A compound is soluble in ether at room temp but not very soluble at -80 deg C. Is ether a good crystallization solvent for the compound?

This is a post lab question in an Organic Chemistry lab. We need to explain if and why ether would make a good solvent in this scenario. I’m pretty sure it wouldn’t, but I can’t exactly come up with a straight explanation. I know the rule is a compound needs to be fairly soluble in a hot solvent and much less soluble in cold solvent. But does the fact that the solute dissolves at room temp affect how practical it would be to use ether as a solvent?

1 Answer

  • Mike A
    Lv 7
    1 year ago
    Favourite answer

    Ether boils at a little over 30 deg C so room temperature is not far from boiling and you can achieve -80 deg with solid CO2/alcohol baths so from a solubility point of view it might look OK. But can you cool and maintain filtration equipment at -80 deg when handling and what about solvent loss when filtering the hot (30 deg) ether solution? Also consider condensation of atmospheric water whilst isolating the purified product.

    It would be better to look for an alternative solvent with a boiling point in a range of 65-100 deg in order to simplify handling problems.

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