Calculate the enthalpy change for the thermite reaction: 2al (s) + fe2o3 (s) →2fe (s) + al2o3 (s), δh∘rxn=-850 kj when 4.00 mol of al undergoes the reaction with a stoichiometrically equivalent amount of fe2o3.

Given:

Enthalpy change ΔH for the thermite reaction = - 850 kJ

Moles of Al involved = 4

To determine:

Reaction enthalpy when 4 moles of Al reacts

Explanation:

The thermite reaction is-

2Al (s) + Fe2O3 (s) → 2Fe (s) + Al2O3 (s)

When 2 moles of Al react the enthalpy change is - 850 kJ

therefore, when 4 moles of Al reacts, the change in enthalpy is-

= 4 moles * (-850) kJ/2 moles = - 1700 kJ

Ans: Enthalpy change is - 1700 kJ