Lab #: 13 Syllabus Topic: Thermal physics You are provided with the following apparatus: 1 Styrofoam cup with a mark on the inside (this mark indicates when 100cm3 of hot pure water is in the cup), Beaker with 100 cm3 of salt water, 1 thermometer, 1 measuring cylinder (large), You will use these apparatus to determine the specific heat capacity of salt water. Theory Specific heat capacity of pure water = 4200Jkg -1K -1 100cm3 of pure water = 100g of pure water (When you are ready for the hot water, it is available in the kettle) 85cm3 of salt water = 100g of salt water 98%Heat lost by the hot pure water = h eat gained by the cold salt water
Diagram
thermometer 100cm3 of salt water
100cm3 of hot pure water
Method:
The salt water is added to the hot pure water
Result:
Discussion Errors, precaution, improvement to method, assumptions Conclusion:
Lab #: 14 Syllabus Topic: Thermal physics You are provided with the following apparatus: 1 balance, 1 boiling tube containing 40 g of water, 1 candle in a holder, 1 retort stand, 1 thermometer You will use these apparatus to determine the energy value in joule per unit mass (J/g) of the candle wax.
Diagram:
Theory
Energy gained by the water =
⅔ energy supplied by the candle
Thermometer
mw x cw x Δθ w = mc x C c mw x cw x Δθ w = (m1 – m m2 ) x C c
Retort Stand
Boiling tube Pure water
-1
-1
Specific heat capacity of water = 4.2 Jg K
Method: Place 40g of water in the boiling tube. Set it on the retort stand. Find the mass of the candle and the holder, m1. Placed the candle under the boiling tube and light it. Heat until the water is 60°C. Put out the flame and find the mass of the candle and the holder, m 2. Result: Discussion Errors, precaution, improvement to method, assumptions Conclusion:
Candle
Candle holder
Lab #: 15 Syllabus Topic: Thermal physics In this experiment you will be required to test the hypoth esis that
ice melts faster i n salt water than i n f resh water ”.
“
You will be provided with 2 Styrofoam cups, 2 thermometers, pure water, salt water, stop watch and ice.
Instructions 1.
Label the two Styrofoam cups PW for pure water and SW for salt water.
2.
Weight 150g of pure water and place it in PW cup.
3.
Weight 150g of salt water and place it in
4.
Place the thermometers in the cups. Record the temperatures of the cup.
5.
Place 1 cube of ice into each cup and simultaneous start the timer. DO NOT STIR.
6.
Record the temperature every ½ minute.
7.
Plot 2 graphs on the same pair of axes.
SW cup.
In this experiment the melting point of naphthalene by plotting a cooling curve.
You will be provided with the following apparatus: Boiling tube, naphthalene, thermometer, retort stand, test tube holder, stopwatch, water-bath, Bunsen burner, tripod, gauze.
Instructions: 1.
Place naphthalene in the boiling tube to about ⅓ of its depth.
2.
Place the boiling tube in a beaker of water standing on a gauze and tripod over a Bunsen b urner.
3.
Heat the water to b oiling until all the naphthalene has liquidified.
4.
Remove the tube and clamp it upright on the retort stand.
5.
Place a thermometer in the boiling tube. (The temperature should be close to 100°C)
6.
Record the temperature and repeat this observation every minute for the 30 minutes. (DO NOT STIR WHEN THE LIQUID STARTS TO SOLIDIFY BECAUSE THE BOILING TUBE WILL BREAK)
7.
Plot a graph of temperature against time.
8.
Read off the melting point from the graph.
