A sample of potassium nitrate (49g) is dissolved in 101g of water at 100°C, with precautions taken to avoid evaporation of any water. The solution is cooled to 30°C and no precipitate is observed. The solution is ________.
A. Hydrated
B. Supersaturated
C. Unsaturated
D. Placated
E. Saturated
I know the difference between the choices, but I don't know how to use that info to answer the question. Help please? Thanks!
3 answers
I can tell you this much. This is a lousy question. The solution COULD be saturated but there is no way to know with the information listed. It IS hydrated for sure. If not saturated, then the solution is unsaturated. So the correct answers are A and either B or C depending. I suspect the question is looking for C to be the correct answer just from the way the problem is stated.
I missed a point here. It could also be supersaturated. I suggest you look up the solubility of KNO3 at 30o C, then you will know.
supersaturated
2 answers