CHEM1101 2013-J-10 June 2013
• Use the standard heats of formation provided to calculate the molar heat of
combustion of liquid methanol, CH3OH, in oxygen to produce CO2 and water.
Your answer must include a balanced chemical equation for this reaction. Show
all working.
Marks
2
Data: Compound H2O(l) CH3OH(l) CO2(g)
ΔfHº / kJ mol–1 –285.9 –238.6 –393.5













Answer:

CHEM1101 2012-N-12 November 2012

• Consider the process H2O(s) H2O(l)
Give the sign of ΔH° at 273 K and explain your choice.
Marks
3






Give the sign of ΔS° at 273 K and explain your choice.






How does ΔG° change with an increase in temperature? Explain your answer.













CHEM1101 2009-N-12 22/07(a)


• Pentane, CH3CH2CH2CH2CH3, burns completely in oxygen to form CO2(g) and
H2O(g). Use the bond enthalpies given below to estimate the enthalpy change for this
process.
Marks
3
Bond Bond enthalpy (kJ mol–1) Bond Bond enthalpy (kJ mol–1)
C–H 414 O–H 463
C–C 346 O–O 144
C=O 804 O=O 498






























Answer:
CHEM1101 2006-N-8 November 2006
• Glucose is a common food source. The net reaction for its metabolism in humans is:
C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O(l)
Calculate ΔH° for this reaction given the following heats of formation.
ΔH°f (C6H12O6(s)) = –1274 kJ mol–1
ΔH°f (CO2(g)) = –393 kJ mol–1
ΔH°f (H2O(l)) = –285 kJ mol–1
Marks
3



















Answer:
If the combustion of glucose is carried out in air, water is produced as a vapour.
Calculate ΔH° for the combustion of glucose in air given that
H2O(l) → H2O(g) ΔH° = +44 kJ mol–1







Answer: