Specific Heat of metals

Purpose:

To determine the amount of energy metals absorb or their specific heats.

Background:

The ability of a substance to absorb or release energy is known as specific heat.
If a substance absorbs energy easily, it is said to have a low specific heat capacity.
Most metals have a low specific heat capacity Which means they will absorb energy easily.

Materials:

• Hot plate
• 1000 ml beaker with 500ml of water
• Thermometer
• Aluminum foil
• Different metal cylinders
• Weight scale
• Styrofoam cup with 150ml of water
• Safety glasses

Safety Rules:

• All students will wear safety goggles once the heat is turned on.
• Do not place any foreign objects on the hot plate.

Procedure:

1. Weigh the different metal cylinders and record in a data table.
2. Place the beaker with the water on a hot plate and turn on high.
3. While the water is heating,take the temperature of the 150ml of water in the cup, and record in a data table as initial temperature.
4. Take the aluminum foil and put a hole in it so that the thermometer fits through the foil, and the foil will cover the styrofoam cup completely.
5. When the water starts boiling, carefully place a metal cylinder into the water.
6. Wait 3 minutes for the metal to heat.
7. Quickly and carefully place the metal cylinder in the styrofoam cup.Quickly place the aluminum foil over the top.
8. Carefully put the thermometer into the cup.
9. When the temperature in the cup quits rising, record in the data table as final temperature.
10. Change the water in the cup so that the initial temperature is the same for each metal.
11. Repeat with the other cylinders making sure that the amount of water in the beaker stays about 500ml.
12. When the last metal has been recorded, turn off the hot plate and allow the metals to cool.
13. Put up the safety glasses and return the metals to the teacher and clean up the lab area.

Results:

• Calculate the heat absorbed by the metals using the following equation:
• Energy gained by water= energy lost by the metal. (Mw x (Tf-Ti)w x Cw = Mm x(Tf-Ti)m x Cm)
• M= mass of water (volume and mass numbers are the same)
• C= specific heat of water= 1 cal/gram
• Tf= final temp. Ti= initial temp.

Conclusions:

1. Did each metal absorb the same amount of energy?
2. What do you think might be the difference in the amount of energy each absorbed?
3. Look at the metals on the periodic chart. Is there a pattern? If so, what is it?

Extension:

Calculate how much the temperature rose in each metal.