Reaction Energy & Hess’s Law Practice Key
What is the heat of formation of sucrose via photosynthesis (6 CO2 + 6 H2O -> C6H12O6 + 6 O2) given the following reactions?
C6H12O6 -> 6C + 6H2 + 3O2 -2919 kJ/mol
C + O2 –> CO2 -393.5 kJ/mol
H2 + ½O2 -> H2O -285.8 kJ/mol
H2 + O2 -> H2O2 -187.8 kJ/mol
6C + 6H2 + 3O2 -> C6H12O6 +2919 kJ
6CO2 –> 6C + 6O2 +2361 kJ
6H2O -> 6H2 + 3O2 +1714.8 kJ
6 CO2 + 6 H2O -> C6H12O6 + 6 O2 +6994.8 kJ
What is the heat of formation of SO2 from S and O2 given the following reactions?
S + 3/2O2 -> SO3 -395.2 kJ/mol
2SO2 + O2 –> 2SO3 -198.2 kJ/mol
C + O2 –> CO2 -393.5 kJ/mol
1
S + 3/2O2 -> SO3 -395.2 kJ
SO3–> SO2 + 1/2O2 +99.1 kJ
S + O2 -> SO2 -296.1 kJ
What is ΔH for CaCO3 -> CaO + CO2 given the following reactions?
Ca + C + 3/2O2 -> CaCO3 -1207.6 kJ/mol
Ca + 1/2O2 –> CaO -634.9 kJ/mol
C + O2 -> CO2 -393.5 kJ/mol
Ca + O2 + H2 -> Ca(OH)2 -893.2 kJ/mol
CaCO3 -> Ca + C + 3/2O2 +1207.6 kJ
Ca + 1/2O2 –> CaO -634.9 kJ
C + O2 -> CO2 -393.5 kJ
CaCO3 -> CaO + CO2 +179.2 kJ
What is ΔHf for 5C + 6H2 -> C5H12 given the following reactions?
C + O2 -> CO2 -393.5 kJ/mol
C + 1/2O2 -> CO -110.5 kJ/mol
H2 + ½O2 -> H2O -285.8 kJ/mol
H2 + O2 -> H2O2 -187.8 kJ/mol
C5H12 + 8O2 -> 5CO2+ 6H2O -3553.6 kJ/mol
5CO2+ 6H2O -> C5H12 + 8O2 +3553.6 kJ
5C + 5O2 -> 5CO2 -1967.5 kJ
6H2 + 3O2 -> 6H2O -1714.8 kJ
5C + 6H2 -> C5H12 -128.7 kJ
What is ΔH for C2H5OH + O2 -> H2O + CO2 given the following reactions?
C + O2 -> CO2 -393.5 kJ/mol
H2 + ½O2 -> H2O -285.8 kJ/mol
2C + 3H2 + 1/2O2 -> C2H5OH -277.0 kJ/mol
C2H5OH -> 2C + 3H2 + 1/2O2 +277.0 kJ
2C + 2O2 -> 2CO2 -787.0 kJ
3H2 + 3/2O2 -> 2H2O -857.4 kJ
C2H5OH + 3O2 -> 3H2O + 2CO2 -1367.4 kJ