Thermite Reaction

1. The thermite reaction demonstrated can be represented with this chemical equation:
   Fe₂O₃(s) + 2Al(s) → Al₂O₃(s) + 2Fe(s)
   Use the following thermodynamic data to calculate ΔH_rxn for this reaction.
   Fe₂O₃(s) ΔH_f = –824 kJ/mol
   Al₂O₃(s) ΔH_f = –1673 kJ/mol
2. Find the heat released for 31.0 g of Fe.
3. Find the final temperature (T_f) for adding that much heat to that much Fe. Useful formulas and data: q = mC(T_f – T_i) T_i = 25°C C = 0.45 J/g°C
4. How much heat is required to bring 31.0 g Fe to 1530°C, the melting point of Fe?
5. How much heat is left over after raising the temperature of the Fe to its melting point?
6. Is the left over heat enough to melt all 31.0 g of Fe if it takes 14.9 kJ/mol to melt it?
   Fe(s) → Fe(l) ΔH = +14.9 kJ/mol
7. Why is it safe to store pre-mixed thermite reaction mixture even though the reaction is, once started, one that cannot be stopped?