Chemistry Boiling Point of Water Lab NAME______
PUROPSE: The purpose of this lab is to verify the boiling point of water.
BACKGROUND:
The solid state has a definite volume and shape. The molecules are so close they are touching and motion is described as vibrational. The liquid state has a definite volume, but no definite shape. Liquids take the shape of their container. The movement of the molecule is described as slipping and sliding and rolling and tumbling. Molecules are close to each other but they are not as close as the solid state. The gas state has no definite shape of volume; gases take on the shape and volume of their container. Gases move in rapid random straight line motion and the individual molecules are far apart and do not touch unless they happen to collide with each other.
A physical property is a property that can be observed or measured without changing the identity of a sample of matter. The melting point is the temperature at which the molecules change from the solid state to the liquid state. The freezing point of a substance is the temperature at which the molecules of a substance change from the liquid state to the solid state. The boiling point of a substance is the point at which a substance changes from a liquid state to a gas state. When a substance is converted from one state of matter to another, the change is called a phase change and is considered to be a physical property.
MATERIALS:
150 mL beaker
Split stopper
Thermometer
Ring stand
Large ring clamp
Small ring clamp
Clamp for thermometer
Stirring rod
PROCEDURE:
1. Assemble you set-up as show in class.
2. Fill your 150 mL with approximately 80-100 mL of water.
3. Put on your goggles and apron.
4. Determine who will read the time and who will stir the water.
5. Place the thermometer into water. The thermometer should not touch the bottom of the test tube.
6. Record temperature immediately.
7. Start the Bunsen burner.
8. The partner in charge of stirring should now be stirring the water in the beaker.
9. Record the temperature every 1/2 minute until the temperature remains the same for three minutes!!
10. Turn off the gas. Remove the thermometer. Use beaker tongs to dump your hot water into the sink. Break down your lab set-up. Be careful that you don't burn yourself.
11. Clean your work area. This includes drying off the table.
12. Wash your hands.
13. Put your FOLDED apron in the upper left hand drawer.
14. Remove you goggles and put them away.
DATA: Boiling Point of Water Lab p. 2
0.0
0.5
1.0
1.5
QUESTIONS:
1. Define the following terms:
· Physical property______
______
· Phase change______
______
· Melting point______
______
· Boiling point______
______
Boiling Point of Water Lab p. 3
2. Graph your data. Remember that you controlled the time at which you took readings and you measured the resulting temperature. Remember to include a title, labels and units. Be sure to draw a smooth curve. You may graph your results using the computer if you wish.
3. What is the boiling point of water?______Where on your graph do you see a phase change?
4. Describe the difference in the motion of the particle as water changes from a liquid to a gas.
5. Describe the change in the position of the water particles as water changes from a liquid to a gas.