Question

Calculate the enthalpy change for the thermite reaction: 2Al(s)+Fe2O3(s)→2Fe(s)+Al2O3(s), ΔH∘rxn=−850 kJ when 10.0 mol of Al undergoes the reaction with a stoichiometrically equivalent amount of Fe2O3. Express your answer to three significant figures and include the appropriate units.

Answer 1

Enthalpy change when 10.0 moles of aluminium reacts with stoichiometrically equivalent ferric oxide is
`-4.25* 10^(3) kJ`.

Step-by-step explanation:

`2Al(s)+Fe_2O_3(s)\rightarrow 2Fe(s)+Al_2O_3(s),\Delta H^o_(rxn)=-850 kJ`

Energy change of the reaction when 2 mole of aluminium reacts with 1 mol of ferric oxide :
`\Delta H^o_(rxn)=-850 kJ`

Energy change of the reaction when 1 mole of aluminium reacts :

`(\Delta H^o_(rxn))/(2)=(-850 kJ)/(2)=-425 kJ`

Enthalpy change when 10.0 moles of aluminium reacts with stoichiometrically equivalent ferric oxide:

`-425 kJ* 10.0 =-4250.0 kJ=-4.25* 10^(3) kJ`