Phase Change Lab You may rip out this page for your lab write up…
Heating Data Table HEATING Time Data Point Temp Observations (liquid/solid)
0:00 1
2
3
4
1:00 5
6
7
8
2:00 9
10
11
12
3:00 13
14
15
16
4:00 17
18
19
20
5:00 21
22
23
24
6:00 25
26
27
28
7:00 29
30
31
32
8:00 33
34
35
36
9:00 37
38
39
40
10:00 41
42
43
44
4
Cooling Data Table
HEATING Time Data Point Temp Observations (liquid/solid)
0:00 1
2
3
4
1:00 5
6
7
8
2:00 9
10
11
12
3:00 13
14
15
16
4:00 17
18
19
20
5:00 21
22
23
24
6:00 25
26
27
28
7:00 29
30
31
32
8:00 33
34
35
36
9:00 37
38
39
40
10:00 41
42
43
44
5
Show all work for the problems!!!
1. What do the symbols for the heat equation represent a. q = ____________________
b. m = ____________________
c. T = ____________________
d. Cp = ____________________
2. Write the equation to find the heat needed to raise the temp of a substance:
3. How much heat is required to raise the temperature of 854 g of water from 23.5oC to 85.0oC? (specific heat of water is 4.184J/goC)
4. Phosphorus trichloride is a compound used in the manufacture of pesticides and gasoline additives. How much heat is required to raise the temperature of 96.7 g PCl3 from 31.7oC to 69.2oC? (specific heat of phosphorus trichloride is 0.874J/goC)
5. Carbon tetrachloride was a very popular organic solvent until it was found to be toxic. How much heat is required to raise the temperature of 10.35g of CCl4
from 32.1oC to 56.4oC? (specific heat of CCl4 is o.856J/goC)
6. How much heat is required to raise the temperature of 25.0g of gold from 20.0oC to 1000oC? (specific heat of gold is 0.129J/g0C)
6
Worksheet #3 SPECIFIC HEAT OF A METAL
1. A 11.2 g piece of metal with an initial temperature of 99.9oC is added to 120.3 g of water with an initial
temperature of 25.0oC. The final temperature is 28.0oC. Calculate the specific heat of the metal. (C for water is 4.184 J/goC)
2. What is the specific heat capacity of the metal below: Metal- initial temp = 120oC Water- initial temp = 19.3oC Metal- final temp = 26.2oC Water- final temp = 26.2oC Mass metal = 20.7 g Mass water = 210.3 g C (metal) = ???? C (water) = 4.184 J/goC
3. What is the specific heat capacity of the metal below: Metal- initial temp = 99oC Water- initial temp = 18oC Metal- final temp = 21.1oC Water- final temp = 21.1oC Mass metal = 4.5 g Mass water = 76.5 g C (metal) = ???? C (water) = 4.184 J/goC
7
4. What is the specific heat capacity of the metal below:
Metal- initial temp = 104oC Water- initial temp = 19.5oC Metal- final temp = 23.5oC Water- final temp = 23.5oC Mass metal = 25.7 g Mass water = 124.3 g C (metal) = ???? C (water) = 4.184 J/goC
5. What is the specific heat capacity of the metal below: Metal- initial temp = 110oC Water- initial temp = 20oC Metal- final temp = 24oC Water- final temp = 24oC Mass metal = 32.4 g Mass water = 120 g C (metal) = ???? C (water) = 4.184 J/goC
6. What is the specific heat capacity of the metal below: Metal- initial temp = 110oC Water- initial temp = 19.4oC Metal- final temp = 26.2oC Water- final temp = 26.2oC Mass metal = 30.7 g Mass water = 220.3 g C (metal) = ???? C (water) = 4.184 J/goC
8
Lab Specific Heat of Metals Data Specific heat capacity of aluminum Trial 1 Data: Mass of calorimeter ________ Mass of calorimeter + water ________ Temperature of hot metal ________ Temperature of water in cup ________ Temp of metal and water ________ Mass of dry metal ________ Calculations: Trial 2 Data: Mass of calorimeter ________ Mass of calorimeter + water ________ Temperature of hot metal ________ Temperature of water in cup ________ Temp of metal and water ________ Mass of dry metal ________ Calculations: Average : Percent Error: Specific heat capacity of copper
9
Trial 1 Data: Mass of calorimeter ________ Mass of calorimeter + water ________ Temperature of hot metal ________ Temperature of water in cup ________ Temp of metal and water ________ Mass of dry metal ________ Calculations: Trial 2 Data: Mass of calorimeter ________ Mass of calorimeter + water ________ Temperature of hot metal ________ Temperature of water in cup ________ Temp of metal and water ________ Mass of dry metal ________ Calculations: Average: Percent error:
10
Worksheet #4 ENTHALPY OF FUSION
1. What is the equation for heat of fusion?
2. What is the equation for heat of vaporization?
3. What are the units for heat of fusion?
4. What are the units for heat of vaporization?
5. If 2083 Joules are used to melt 5.26 grams of aluminum, what is the heat of fusion of aluminum?
6. If the same amount (5.26 g) of zinc is melted, it takes 579 Joules to completely melt the sample. What is the heat of fusion of zinc?
7. How much energy is needed to heat a 125 g sample of water from 20 °C to 100 °C? (Note that this is a specific heat problem)
11
8. How much energy does it take to boil a 125 g sample of water? (∆Hvap for water = -2257 J/g)
9. How much energy does it take to heat 125 g of steam from 100 °C to 110 °C? (Specific heat of steam= 2.01 J/g °C)
10. What is the mass of a sample of Nickel, which completely melts after 3120 J of heat? (∆Hfus of nickel is 298 J/g)
11. What is the enthalpy of fusion of ice in J/g if 26.61g of ice is needed to change the temperature of 99.80g of water from 23.4oC to 4.0oC?
12. Calculate the percent error for the data in question #11 (actual is 334 J/g)
12
Lab Enthalpy of Fusion Data Trial 1 Data: Mass of calorimeter ________ Mass of calorimeter + water ________ Initial temperature of water in cup ________ Final temperature of water in cup ________ Mass of melted ice ________ Calculations: Trial 2 Data: Mass of calorimeter ________ Mass of calorimeter + water ________ Initial temperature of water in cup ________ Final temperature of water in cup ________ Mass of melted ice ________ Calculations: Average: Percent Error:
13
Worksheet #5 ENTHALPY OF SOLUTION
1. What is the equation we will use to find the enthalpy of solution?
2. What is the enthalpy of solution in J/g if 5.45 g of NaOH is dissolved into 124 g of water. The temperature of the water changes from 23oC to 26oC. Is this exothermic or endothermic?
3. What is the enthalpy of solution if 7.82g of NaNO3 is dissolved in 195.34 g of water. The temperature of the water changes from 25oC to 19.5oC. Is this exothermic or endothermic?
4. What is the enthalpy of solution if 6.34 g of KOH is dissolved into 98.4 g of water. The temperature of the water changes from 24.5oC to 22.0oC. Is this exothermic or endothermic?
5. What is the enthalpy of solution if 7.58 g of HCl is put into 140 g of water. The temperature of the water changes from 22.5oC to 26.3oC. Is this reaction exothermic or endothermic?
14
Lab Enthalpy of Solution Data
Sodium hydroxide Trial 1 Data: Mass of calorimeter ________ Mass of calorimeter + water ________ Temperature of water ________ Mass of NaOH (about 5 g) ________ Temperature of solution ________ Calculations: Percent Error: Trial 2 Data: Ammonium Nitrate Trial 1 Data: Mass of calorimeter ________ Mass of calorimeter + water ________ Temperature of water ________ Mass of NH4NO3 (about 5 g) ________ Temperature of solution ________ Calculations: Percent Error:
15
Review Worksheet #6
130- e
100- d
Temp.
c
b
0-
a
-20-
Time
Indicate the letter that best answers the questions:
1. Where does boiling occur __________
2. Liquid is being heated _________
3. Particles have the least molecular movement __________
4. Where the greatest amount of potential energy is absorbed __________
5. Where gas is being heated __________
6. Melting occurs here __________
7. Where particles exhibit the greatest amount of kinetic energy __________
8. Where particles show the least attraction for each other __________
9. Freezing occurs here __________
10. Where condensation occurs __________
11. Where particles have the most potential energy __________
12. Particles have a definite shape and volume __________
13. Particles have no definite shape and volume __________
The equation for calculating the heat required to warm a sample is:
16
14. When a hot metal is added to cool water, the metal (loses or gains) energy and the water (loses or
gains) energy.
15. Calculate the specific heat for the metal from the following data:
