Download Thermodynamics Practice Worksheet #1 1. For the reaction: S8(s) +

Thermodynamics Practice Worksheet #1
1. For the reaction:
S8(s) + 8 O2(g) 8 SO2(g) ΔH = –2368 kJ
a) How much heat is evolved when 25 moles of sulfur is burned in excess oxygen?
b) How much heat is evolved when 275 grams of sulfur is burned in excess oxygen?
c) How much heat is evolved when 150.0 grams of sulfur dioxide is produced?
2. Using the enthalpies of formation listed in Appendix Four (A21) calculate the ΔH for the following
reaction. Label each as endothermic or exothermic.
3.
a)
CaO(s) + CO2(g)  CaCO3 (s)
b)
SO3(g) + H2O(l)  H2SO4(aq)
c)
C4H10(g) + O2(g)  CO2(g) + H2O(l)
2 Fe(s) + 3/2 O2(g) → Fe2O3(s)
ΔH°f = -824kJ mol-1
Iron reacts with oxygen to produce iron(III) oxide as represented by the equation above. A 75.0g sample
of Fe(s) is mixed with 11.5L of O2(g) at 2.66atm and 298K.
a) Calculate the number of moles of each of the following before the reaction begins.
i. Fe(s)
ii. O2(g)
b) Identify the limiting reagent when the mixture is heated to produce Fe2O3(s). Support
your answer with calculations.
c) Calculate the number of moles of Fe2O3(s) produced when the reaction proceeds to
completion.
The reaction represented below also produces iron(III) oxide. The value of ΔH° for the reaction is 280.kJ per mol of Fe2O3(s) formed.
2FeO(s) + ½ O2(g) → Fe2O3(s)
d) Calculate the standard enthalpy of formation of FeO(s).