Question

If the solubility of NH₄NO₃ in 50 mL of H₂O is 59.0 g at 0°C and 205.8 at 60°C, label each of the following solutions as unsaturated, saturated, or supersaturated. If more solid is added than can dissolve in the solvent, assume that undissolved solid remains at the bottom of the flask. Select the single best answer for each part.

Adding 61.0 g to 50 mL of H₂O at 60°C and siowly cooling to 0°C to give a clear solution with no precipitate
a. Unsaturated
b. Saturated
c. Supersaturated

Answer 1

The solution that results from dissolving 61.0 g of NH4NO3 in 50 mL of water at 60°C and cooling it to 0°C without any precipitate forming is supersaturated, as it contains more solute than the maximum solubility at 0°C. Option C is the correct answer.

Step-by-step explanation:

The question at hand involves the concept of solubility and the different types of solutions: unsaturated, saturated, and supersaturated. To address it, we must consider the solubilities given for NH4NO3 at different temperatures.

Initially, 61.0 g of NH4NO3 is added to 50 mL of water at 60°C. Since the solubility at 60°C is 205.8 g, all the solute will dissolve, creating an unsaturated solution. However, when this solution is slowly cooled to 0°C without any precipitate forming, it becomes supersaturated because the solubility at 0°C is only 59.0 g, and so the solution still contains more dissolved solute (61.0 g) than what is soluble at that temperature.

Therefore, the correct option for a solution obtained by adding 61.0 g NH4NO3 to 50 mL of H2O at 60°C and cooling to 0°C without any precipitate is (c) Supersaturated.