Question

I have part 1 and 2 but part 3 is a no go. how do

I even?

The process illustrated here takes place at constant pressure. Reaction

Answer 1

Part 3 : $\Delta$H^o_rxn = -791.2 kJ

Explanation

The balanced equation for formation of 1 mole of product is :

SO₂ (g) + 1/2 O₂ (g) $\rightarrow$ SO₃ (g)

$\Delta$H^o = $\Delta$H^o_f products - $\Delta$H^o_f reactants

$\Delta$H^o = $\Delta$H^o_f SO₃ (g) - [$\Delta$H^o_f SO₂ (g) + (1/2) * ($\Delta$H^o_f O₂ (g))]

$\Delta$H^o = (-395.7 kJ/mol) - [(-296.8 kJ/mol) + (1/2) * (0)]

$\Delta$H^o = -395.7 kJ/mol + 296.8 kJ/mol

$\Delta$H^o = -98.9 kJ/mol

$\Delta$H^o_rxn = ($\Delta$H^o) * (moles SO₃ formed)

$\Delta$H^o_rxn = (-98.9 kJ/mol) * (8.00 mol)

$\Delta$H^o_rxn = -791.2 kJ