More Supersaturated Solutions - Per 8!

I just had to include these great pictures from period 8's supersaturated solutions lab; you can really see the crystals!

Temperature Dependent Solubility of KNO3

Today we generated a solubility curve for KNO3.

SUPERsaturated solutions!

We have been learning about the concept of solubility and different types of solutions based on the amount of solute dissolved.

Today we did a lab experiment where we created unsaturated, saturated, and supersaturated solutions!

The solute we used was sodium thiosulfate.

We first dissolved a small amount of solute in water to create an unsaturated solution, which looks somewhat clear with no undissolved solid.

Then we added more solute until the solution was saturated, as evidenced by the undissolved crystals on the bottom of the test tube.

Then we heated the mixture as the solubility of the sodium thiosulfate increases as the temperature increases.

 Finally, we cooled the test tube to reduce the solubility, and "disturbed" the solution by adding a single additional crystal of the solute. The excess solute crystallized out in a dramatic fashion!

Solutions Concept Map

We have started a concept map for Unit 10 - Solution Chemistry. This should help us relate all the vocabulary and complex ideas. We plan to continue to add to our concept map throughout the unit.

Factors Affecting Rates of Dissolution

Today we performed a small inquiry experiment to determine which factors affect the rates of dissolution. Students had to design their own procedure to test how surface area, solvent temperature, and stirring affected how much sugar dissolved in water.

The students did a great job with setting up their experimental constants such as the amount of water, amount of sugar, and method of stirring.

Be sure to ask the chemists what they discovered!