Answer to Question #181236 in General Chemistry for nonethemore

Question

Procedure:

1. Pour about 100 mL of water into a container/pot.

2. Place the container/pot on a stove and heat it for about a minute. Notice also if the water is already boiling or not.

3. Then, carefully touch the side of the container/pot (be very careful in touching the container/pot). Record your observation.

4. Next, place an ice into water. What do you observe? Record your observation.

5. Put water in a glass and pour 1 teaspoon of salt. Which substances flows on top? Record your observation.

6. Using the different solid substances (available at home) dissolve each in a glass of water with one teaspoon each. Observe what happens. Record your observation.

Guide Questions:

1. Observation about the temperature during boiling period as you touch the container/pot (Observation in Procedure 3)

2. Observation as you place an ice in water. (Observation in Procedure 4)

Answer 1

Heat goes into the liquid as it vaporizes. Heat leaves the gas as it condenses. During a change in state the heat energy is used to change the bonding between the molecules. In the case of melting, added energy is used to break the bonds between the molecules.