Heat of Combustion Experiment

Topics: Energy, Heat, Thermodynamics Pages: 4 (761 words) Published: November 6, 2006
Alkanols Heat of Combustion

Aim: To determine the molar heat of combustion of methanol, ethanol and 1-propanol

Materials:
3 spirit burners, one containing methanol, one containing ethanol and one containing 1-propanol. A thermometer
A copper calorimeter
100 ml measuring cylinder
Retort stand and clamps
Stopwatch
Matches
Electronic balance

Safety assessment:
This experiment contains flammable materials remove loose clothing such as ties which could be set alight. Wear safety glasses!
Ensure equipment placement is safe and does not danger nearby students.

Method:
1.Set up the experiment as shown in the diagram below.

2.Measure exactly 100 milliliters of water using the measuring cylinder and carefully pour it into the Copper calorimeter. Put the thermometer in the water to measure the temperature of the water. 3.Weigh the spirit burner and record the mass

4.Record the temperature of the water in the Copper calorimeter. 5.Pull the cap off the spirit burner and light the cloth wick remembering to start the stopwatch as soon as the wick lights 6.Record the temperature of the water after 1, 2 and 3 minutes, at 3 minutes replace the cap on the spirit burner. 7.Reweigh the burner and record. Start experiment again at step 2 with a different alkanol. Each alkanol should be tested at least 3 times.

Results:

MethanolTest OneTest TwoTest Three
Mass before (g)299.34298.34296.93
Temperature Before (°c)232423
After 1 Minute (°c)303329
After 2 Minutes (°c)374139
After 3 Minutes (°c)434849
Mass after (g)298.34297.29295.99

EthanolTest OneTest TwoTest Three
Mass before (g)276.78275.04273.86
Temperature Before (°c)232323
After 1 Minute (°c)293233
After 2 Minutes (°c)404446
After 3 Minutes (°c)535558
Mass after (g)275.42273.86272.63

1-PropanolTest OneTest TwoTest ThreeTest Four
Mass before (g)189.63187.64186.08184.81
Temperature Before (°c)232423...