Question

Based on the reaction below
2Al(s) + Fe2O3(s)= Al2O3(s) + 2Fe(l)
Calculate the heat releases in kilojoules per gram of Al reacted with Fe2O3.the standard enthalpy of formation for Fe(l) is 12.40kJ/mol.

Answer 1

To calculate the heat released per gram of Al reacted with Fe2O3, we first need to calculate the molar mass of Al.

The molar mass of Al is 26.98 g/mol.

Next, we need to calculate the moles of Al reacting with Fe2O3. From the balanced chemical equation, we see that 2 moles of Al react with 1 mole of Fe2O3.

Since the molar mass of Fe2O3 is 159.69 g/mol, we can calculate the moles of Al reacting with Fe2O3:

1 mol Al = 26.98 g Al
x mol Al = 159.69 g Fe2O3

x = (159.69 g Fe2O3) / (159.69 g/mol Al) = 5.92 mol Al

The heat released per mole of Al reacted is given by the reaction:

2Al(s) + Fe2O3(s) = Al2O3(s) + 2Fe(l)

ΔH = Σ(nΔHf(products)) - Σ(mΔHf(reactants))

ΔH = [2(0) + 2(12.40 kJ)] - [0 + 0] = 24.80 kJ

Therefore, the heat released per mole of Al is 24.80 kJ.

Now, to calculate the heat released per gram of Al:

24.80 kJ / 26.98 g/mol = 0.919 kJ/g

Therefore, the heat released per gram of Al reacted with Fe2O3 is 0.919 kJ/g.