Answer to Question #133077 in General Chemistry for Frederick Jude Evangelista

Question

Calculate the standard enthalpy change for the reaction
2Al(s)+〖Fe〗_2 O_3 (s)→2Fe(s)+〖Al〗_2 O_3 (s)
given that
2Al(s)+3/2 O_2 (g)→〖Al〗_2 O_3 (s) ∆H_rxn^°=-1669.8 kJ/mol
2Fe(s)+3/2 O_2 (g)→〖Fe〗_2 O_3 (s) ∆H_rxn^°=-822.2 kJ/mol

Answer 1

given that

2Al(s)+3/2 O₂ (g)→Al₂ O₃ (s) ∆H_rxn°=-1669.8 kJ/mol................................1.

2Fe(s)+3/2 O₂ (g)→Fe₂O₃(s) ∆H_rxn°=-822.2 kJ/mol ....................................2.

For Reaction '

2Al(s)+Fe₂O₃(s)→2Fe(s)+Al₂O₃ (s)

∆H_rxn° = eqn 1 - eqn 2 .

= -1669.8 - ( - 822.2 ) kj / mole . = -847.6 kj / mol .

 standard enthalpy change for the reaction = - 847.6 kj / mole .

2Al(s)+ Fe₂ O₃ (s)→2Fe(s) + Al₂ O₃ (s)