Catalyst: 1.What is the solubility of potassium nitrate in 80 g of water at 60°? g KCl is dissolved in 100 g of water that is at 80°. What would happen if the amount of KCl was doubled? As you come in… Have out C.2 questions and worksheet. Objectives: 1. I know the relationship between temperature and the amount of substance that an dissolve. 2. I can describe a method for collecting data in the laboratory to create a solubility curve. 3. I can identify some of the possible errors in the lab and predict how these errors would affect the data.

3. Which substance is most soluble at 60° C? 5. What is the solubility of potassium nitrate at 90° C? 7. You have a solution of sodium nitrate containing 140 g at 65° C. Is the solution saturated, unsaturated, or supersaturated? 9. A solution of potassium iodide at 70° C contains 200 g of dissolved solute in 100 cm 3 water. The solution is allowed to cool. At what new temperature would crystals begin to start forming?

11. If a saturated solution of KNO 3 at 20°C is heated to 80 °C, how much more KNO 3 could be dissolved? 13. How much NaCl will dissolve in 350 g of water at 70 °C? 15. How much KNO3 will dissolve in 5.6 kg of water at 80 °C? *3.5=140gNaCl 5.6 g * 1000g/1kg = 5600 g 170/100 = ?/5600 g 170*5600/100= 9520 g KNO =140g KNO3

Solubility Lab Measure out exactly 4.00 grams of the salt (NH 4 Cl) and place in a large test tube. Add exactly 10 mL of distilled water to the test tube containing the salt. Place the thermometer in the tube (may be used to stir the solution) Weigh 4.00 g NH4Cl Put NH4Cl in test tube Measure 10 mL DI water in graduated cylinder and add to test tube 4 g NH 4 Cl and 10 mL DI water

Using a hot water bath dissolve the salt. *Using TEST TUBE HOLDER* Hotplate water Place beaker with water on hotplate to heat Place tube with 4 g NH4Cl and 10 mL DI water in water bath Wait until there is no solid present and remove Hotplate water 4 g NH 4 Cl and 10 mL DI water Hotplate clear water

Constructing a Solubility Curve Data Temperatures at which the given mass of solute crystallized 4 g5 g6 g7 g Mean