ICY HOT LAB 2014
Purpose: to observe the temperature changes as water changes phase.
In your lab NB, complete the followingPrelab questions:
- Sketch the lab set-up.
- What is the “system” that you will be observing?
- How will energy be added to the system (Q, W or R)? How do you know this?
- Identify the independent variable and the dependent variable in the lab.
- Make a prediction of how temperature will change as water changes from a solid to a liquid to a gas. Make a sketch as part of your prediction.
- Make a particle diagram of each phase of water…solid, liquid and gas. Draw arrows between the phases and label with the following: condensation, vaporization, solidification, melting, sublimation, deposition.
- Make a data table to record temperature of water every 30 secs.
Materials:
250 mL beakertap waterice cubesgraduated cylinder
Stirring rodhot platethermometer
Procedures:
- DO NOT START HEATING HOT PLATE UNTIL STEP 6.
- Select your glassware and clean it. Be sure to dry it completely.
- Measure 30 mL of tap water and add to your 250 mL beaker.
- Add approximately 100 mL of ice to your beaker. Allow beaker to sit for 2 minutes.
- Place the beaker on the hot plate and record the initial temperature.
- Plug the hot plate in, set at a medium temperature level and constantly stir the water and ice throughout the experiment.
- Record the temperature every 30 seconds and record this information in the data table.
- Record all qualitative and quantitative observations of the melting ice. (Question guide on back of page)
- Record the temperature and the time when the all of the ice has completely melted. This is a very important data point on your graph.
- Keep recording the temperature until all of the water is boiling; be sure to record the exact temperature and time when all of the water in your beaker is boiling. This is a very important data point on your graph.
- Continue recording the temperature until the water has been boiling for THREE minutes.
- Unplug the hot plate and allow the beaker and water to cool. Then pour the contents down the drain. Be careful not to burn yourself.
- Dry off your supplies and return them to cart.
Icy-Hot Lab Question Guide: Record in lab NB.
- As you heat the beaker with a gentle flame, what is happening to the temperature of the system. How do you know?
- What phases are present in the beaker?
- Draw particle diagrams for particle level changes occurring as the ice melts.
Ice and a little water
Temperature =
Time = / Half ice and half water
Temperature =
Time = / All water
Temperature =
Time =
- What happens to the kinetic energy of the system as the ice is melting? How do you know?
- When all the ice has melted, what happens to the temperature of the system?
- What phase(s) is (are) present in the beaker at this time?
- Draw particle diagrams for particle level changes occurring as the water heats up.
Ice just melted
Temperature =
Time = / Water at room temperature
Temperature =
Time = / Hot water
Temperature =
Time =
- What happens to the kinetic energy of the system as the water continues to heat? How do you know?
- When the water starts to boil, what happens to the temperature of the system?
- What phase(s) is (are) present in the beaker at this time?
- Draw particle diagrams for particle level changes occurring as the water boils.
Water just starts boiling
Temperature =
Time = / Water boiling
Temperature =
Time = / Some water boiled away
Temperature =
Time =
- What happens to the kinetic energy of the system as the water is boiling? How do you know?