Lab Report Latent Heat Of Vaporisation Of Water
Nicolò Cortese, Bogdan Hurjui, Bertram Kress Fugl
Mrs. Baines
S5ENA Physics
8/2/15
Lab Report
Experiment to measure the latent heat of vaporisation of water Theory
Latent heat of vaporisation is when a liquid is heated enough to start boiling, at this point, even if the source of heat keeps heating the liquid, the liquid’s temperature will not rise any further until all of the liquid is converted to gas. For example, if water is boiling in a kettle, and the kettle is left on whist the water is boiling, the water’s temperature will not exceed 100°C because all the heat energy from the kettle is needed for all of the water to evaporate.
Apparatus
Water
Calorimeter
Insulating mat
Mass balance
Electric heater
Ammeter
Voltmeter
Stopwatch
2 short wires, 3 long ones
Kettle
Square of insulating wool
Method
1. Circuit made
2. Calorimeter on insulating wool placed on mass balance
3. Heater placed in calorimeter
4. Mass balance set to zero
5. Water heated in kettle then poured into calorimeter
6. Heater switched on, p.d. increased to 12V
7. Recording started when water boiling: Mass of water recorded every minute for 12 minutes
8. Table made showing Minutes, Volts, Amps and grams
Results
Min
0
1
2
3
4
5
6
7
8
9
10
11
12
Voltage (V)
12
12
12
12
12
12
12
12
12
12
12
12
12
Current (A)
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
Mass (g)
252.5
251.4
250.8
249.7
249
247.7
247
245.5
244.3
243.2
242.1
240.9
239.8
Graph
M(gradient)= Mass loss per minute= 1.086g/min
Calculations to find L
Energy transferred =mL
P=VI = 12*3.7 =44.4W
Energy from heater= Pt= 44.4*720= 31,968 Joules
Energy transferred =mL
31,968 =0.0127*L
L =2,517,165.35433 J/kg
Comparison
Specific heat capacity of water is the energy it takes to increase the temperature of 1 kg of water by 1° whilst the latent heat capacity is the energy needed to turn 1kg of water into steam. In both cases it is heating up the water.
Conclusion
Our result is very close to that of the book
Mrs. Baines
S5ENA Physics
8/2/15
Lab Report
Experiment to measure the latent heat of vaporisation of water Theory
Latent heat of vaporisation is when a liquid is heated enough to start boiling, at this point, even if the source of heat keeps heating the liquid, the liquid’s temperature will not rise any further until all of the liquid is converted to gas. For example, if water is boiling in a kettle, and the kettle is left on whist the water is boiling, the water’s temperature will not exceed 100°C because all the heat energy from the kettle is needed for all of the water to evaporate.
Apparatus
Water
Calorimeter
Insulating mat
Mass balance
Electric heater
Ammeter
Voltmeter
Stopwatch
2 short wires, 3 long ones
Kettle
Square of insulating wool
Method
1. Circuit made
2. Calorimeter on insulating wool placed on mass balance
3. Heater placed in calorimeter
4. Mass balance set to zero
5. Water heated in kettle then poured into calorimeter
6. Heater switched on, p.d. increased to 12V
7. Recording started when water boiling: Mass of water recorded every minute for 12 minutes
8. Table made showing Minutes, Volts, Amps and grams
Results
Min
0
1
2
3
4
5
6
7
8
9
10
11
12
Voltage (V)
12
12
12
12
12
12
12
12
12
12
12
12
12
Current (A)
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
Mass (g)
252.5
251.4
250.8
249.7
249
247.7
247
245.5
244.3
243.2
242.1
240.9
239.8
Graph
M(gradient)= Mass loss per minute= 1.086g/min
Calculations to find L
Energy transferred =mL
P=VI = 12*3.7 =44.4W
Energy from heater= Pt= 44.4*720= 31,968 Joules
Energy transferred =mL
31,968 =0.0127*L
L =2,517,165.35433 J/kg
Comparison
Specific heat capacity of water is the energy it takes to increase the temperature of 1 kg of water by 1° whilst the latent heat capacity is the energy needed to turn 1kg of water into steam. In both cases it is heating up the water.
Conclusion
Our result is very close to that of the book