6.03 Calorimetry Lab

Words: 765
Pages: 4

Calculate the mass of potassium nitrate and the mass of water in each solution

Calculate the ratio of the mass of potassium nitrate to the mass of water for each solution.

Multiply the mass ratio by 100 to determine the concentration of each saturated solution in grams of potassium nitrate per 100 grams of water.

Plot a graph of solubility of potassium nitrate (in g of solute/100 g of water) on the y-axis versus temperature on the x-axis. Scale each axis as necessary. Draw a smooth, best-fit curved line through the data points.
Using your graph, estimate the solubility of potassium nitrate in water at (a) 0 °C; (b) 50 C; and (c) 100 °C.

Using your graph, predict the temperature at which each of the following mixtures of potassium nitrate in water would form a saturated solution: (a) 25 g KNO3 in 25 g H2O; (b) 100 g KNO3 in 250 g H2O.

Define the terms saturated, unsaturated, and supersaturated as they apply to solutions.
…show more content…
You cannot dissolve any more solute in a saturated solution. Unsaturated means, “able to hold more,” so an unsaturated solution can dissolve more solute. You can add more solute to an unsaturated solution until it reaches its saturation point. Supersaturated means, “holding more than the maximum,” so a supersaturated solution has more solute dissolved in it than the solvent can hold. A supersaturated solution is created by saturating a solution, at a higher temperature than is desired, before cooling it down. By agitating or providing a seed crystal/surface, the supersaturated solution begins to crystalize the excess solute out until it reaches the saturation point at that