Question

If your unknow solid has an impurity that is insoluble in cyclohexane, will this impurity result in the molar mass of the unknown solid being recorded as high, low, or unaffected? Explain.

Answer 1

Answer:

High

Explanation:

When the unknown compound contains an impurity that is insoluble in cyclohexane, the solute will not dissolve in the solvent (cyclohexane) completely. ∆T of the solution would be smaller than it is supposed to be, when compared to a compound without such insoluble impurity. Molecular weight determination won't be accurate because the molecular weight obtained will be higher as a result of the fact that the mass of the solute would include the actual solute that is changing the temperature and the excess mass of the impurity.