PART I: THE EFFECT OF SALT ON THE PHASE TRANSITION OF WATER
1 measuring cup (that can measure ~500 ml in volume)
1 thermometer that measures below 0C
4 containers (each with a volume of ~500 ml)
Ice (~150g or one tray’s worth of ice cubes)
7 tsp salt
1. Pour 0.5 cups (100 mL) tap water (room temperature water) into each of the four containers.
2. Start with the first container of water. Add one fourth of the ice (~37.5 g) and stir quickly.
3. While stirring or shaking the container to keep the water circulating, measure the temperature of the ice bath. Wait until the thermometer stays at one temperature for about 10 seconds before recording.
4. Move on to the second container of water. Dissolve 1 tsp (~5g) of salt in the tap water before adding the ice (~37.5 g). Repeat step 3.
5. Move on to third container of water. Dissolve 2 tsp (~10g) of salt in the tap water before adding the ice (~37.5 g). Repeat step 3.
6. Move on to the fourth container of water. Dissolve 4 tsp (~20g) of salt in the tap water before adding the ice (~37.5 g). Repeat step 3.
7. Enter your data in the response fields below for credit.
(4 points possible)
In the response fields below, enter your estimate for the salt concentration in g/ml (but without including the unit in your answer) when adding:
0g of salt?
5g of salt?
10g of salt?
20g of salt?