homeworkkkkkkkk

Question

the overall reaction in a commercial heat pack can be represented as:

4Fe(s)+3O2(g) --> 2Fe2O3(s) delta H= -1652kJ

a)How much is relased when 4.00 moles of ron are reacted with excess O2?

Heat= kJ

b) how much heat is released when 1.00 moles of Fe2O3 is produce?

Heat= kJ

c) How much heat is released when 1.20g iron is reactedwith excess O2?

Heat= kJ

d)How much heat is released when 10.8g Fe and 1.50 g O2 are reacted?

Heat= kJ

Answer 1

4Fe(s) + 3O₂(g)---> 2Fe₂O₃(s)

A. -1652 kJ/4 mol Fe x 4.00 mol Fe = -1652 kJ

B. -1652 kJ/2 mol Fe₂O₃ x 1 mol Fe₂O₃ = -826 kJ

C. 1.20 g Fe x 1 mol Fe/55.85 g x -1652 kJ/4 mol = -8.87 kJ

D. 10.8 g Fe x 1 mol Fe/55.85 g = 0.193 moles Fe

1.50 g O₂ x 1 mol/32 g = 0.0469 moles O₂

O₂ is limiting as the mole ratio in balanced eq. is 3:4 for O₂:Fe

0.0469 moles O₂ x -1652 kJ/3 mol O₂ = -25.8 kJ