Deterioration of buildings, bridges, and other structures through the rusting of iron costs millions of
dollars every day. Although the actual process also requires water, a simplified equation (with rust
shown as Fe₂O3) is:
4 Fe(s) + 3 O₂(g) → 2 Fe₂O3(s)
(a) What is the AHrxn when 0.250 kg of iron rusts?
x 10
kJ
x 10
AHrxn-1.65 × 10³ kJ
(b) How much rust forms when 4.50 × 10³ kJ of heat is released?
g Fe₂O3
