Don’t forget:

Change your clocks AHEAD 1

hr on Saturday

night!

Friday, March 7th: “A” DayMonday, March 10th: “B” Day

AgendaCheck lab write-upsLab discussionLab: “Making a Solubility Curve for KNO3”

Lab will be due next time…

“Making a Solubility Curve for KNO3”Lab Hints

1. The granular KNO3 will roll around on the balance if you use weighing paper – use a small weighing boat instead.

2. Use DISTILLED WATER instead of water out of the tap to prepare your test tubes.

3. Make sure your measurements are ACCURATE – 2.0 g KNO3 and 5.0 mL of water, etc. Use squirt bottles to get exactly 5.0 mL of water if needed.

“Making a Solubility Curve for KNO3”Lab Hints

4. When dissolving the KNO3 in the hot water bath, BE CAREFUL putting in the rubber stopper and shaking the test tube – the test tube will be HOT!

5. DO NOT shake the test tube too vigorously – the solid KNO3 will stick to the sides of the test tube above the water level.

“Making a Solubility Curve for KNO3”Lab Hints

4. When the KNO3 has dissolved, set the test tube in the rack to cool – do not disturb the test tube as it cools.

5. When you first see signs of crystals forming, put in the temperature probe and record the temperature. You will need to WATCH CLOSELY!

6. Be sure to WIPE OFF the temperature probe each time.

“Making a Solubility Curve for KNO3”Calculations

Units for solubility curves are generally grams solute100 mL H2O

you will need to use PROPORTIONS to convert your data:

2.0 g KNO3 = X g KNO3

5.0 mL of H2O 100 mL H2O

Solve for X

“Making a Solubility Curve for KNO3”Don’t forget to complete your REFLECTION

STATEMENT!Don’t forget to update your TABLE OF

CONTENTS!Please use the squirt bottle of soap to clean off

your lab table when you finish.

Be safe and have fun!

Lab will be due next time…