All simulations

Potassium Nitrate Solubility Lab

Prepare tubes in any order, dissolve, cool, record and graph.
Stop Medium 100%

Virtual laboratory

Drag 2.0 g KNO₃ scoops and 5.0 mL water portions into tubes, then move tubes freely between stations.

Drag reagents into a rack tube
2.0 g KNO₃ one scoop per drag
5.0 mL H₂O one portion per drag
Test-tube rack
Hot water bath · target 90 °C
22.0 °C
Cool water bath
Bath 15.0 °C
Drag tubes between the rack, hot bath and cool bath. A crystallised tube may be reheated and redissolved.
Virtual laboratory: no real flame or chemicals.

Method

Drag 2.0 g KNO₃ scoops into the four rack tubes until they contain 2.0 g, 4.0 g, 6.0 g and 8.0 g. Drag one 5.0 mL water portion into each tube.
Move any prepared tubes into the hot water bath. Turn on the burner and heat the bath towards 90 °C.
Select and stir each heated tube until the solid KNO₃ has completely dissolved and the solution is clear.
Move a dissolved tube to the cool water bath, rack or another suitable position and watch the thermometer. Crystals form at the same temperature for that mixture wherever the tube is cooling.
When crystals first appear, read the thermometer and type the result into the data table. Reheat the tube above that temperature and stir to dissolve the crystals again.
Calculate g KNO₃ per 100 g H₂O, enter your own results, place your own points and draw your own curve of best fit.
Cooling method: place the test tube in a cool water bath. Do not cool it under running water.

Results, graph and questions

Enter your own observations. Calculate solubility using m(KNO₃) ÷ m(H₂O) × 100. Assume 5.0 mL H₂O has a mass of 5.0 g.

Tubem(KNO₃)m(H₂O)Your g KNO₃ per 100 g H₂OYour crystallisation temp.Graph