- Safety Glasses
- Stand Boss and Clamp
- Thermometer
- 50ml Measuring Cylinder
- Copper Can + Lid
- Weighing Balance
- Spirit Burner containing: Methanol. Ethanol. Propanol. Butanol. Octanol.
- Stirring Rod
Data Collection and Processing:
Results:
Energy transferred to the water
q = mc∆T
Methanol
Temperature change: (63.93 – 25.67) = 38.26°C
Mass change: (234.56 – 235.78) = -1.22
Energy transfer:
q = (50cm3) (4.18JK-1g-1) (38.26°C)
= 7996.34 J
= 7996.34 ÷1000
q = 7.9963 KJ
Enthalpy Change ΔH:
(-1.22g) ÷(32 gmol-1) = - 0.038mol-1
(7.9963 KJ) ÷ (- 0.038mol-1)
ΔH = -210.43 KJmol-1
Ethanol
Temperature change: (62.70 – 24.70) = 38 °C
Mass change: (277.75 – 278.59) = -1.09
Energy transfer:
q = (50cm3) (4.18JK-1g-1) (38 °C)
= 7942 J
= 7942 ÷1000
q = 7.9420 KJ
Enthalpy Change ΔH:
(-1.09g) ÷(46 gmol-1) = - 0.024mol-1
(7.9420 KJ) ÷ (- 0.024mol-1)
ΔH = -330.917 KJmol-1
Propanol
Temperature change: (62.17 – 24.97) = 37.2°C
Mass change: (242.67 – 243.72) = -1.12
Energy transfer:
= 7774.8 J
= 7774.8 ÷1000
q = 7.7748 KJ
Enthalpy Change ΔH:
(-1.12) ÷(60gmol-1) = - 0.019mol-1
(7.7748 KJ) ÷ (- 0.019mol-1)
ΔH = -409.200 KJmol-1
Butanol
Temperature change: (58.03 – 24.67) = 33.36°C
Mass change: (249.86 – 250.34) = -0.48
Energy transfer:
q = (50cm3) (4.18JK-1g-1) (33.36 °C)
= 6972.24 J
= 6972.24 ÷1000
q = 6.9722 KJ
Enthalpy Change ΔH:
(-0.48) ÷(74gmol-1) = - 0.006mol-1
(6.9722 KJ) ÷ (- 0.006mol-1)
ΔH = -1162.033 KJmol-1
Octanol
Temperature change: (52.30 – 25.20) = 27.1°C
Mass change: (260.61– 261.18) = -0.57
Energy transfer:
q = (50cm3) (4.18JK-1g-1) (27.1 °C)
= 5663.9 J
= 5663.9 ÷1000
q = 5.6639 KJ
Enthalpy Change ΔH:
(-0.57) ÷(130gmol-1) = - 0.004mol-1
(5.6639 KJ) ÷ (- 0.004mol-1)
ΔH = -1415.975 KJmol-1