Answer:
The correct option is;
B. -112 kJ
Explanation:
The parameters given are;
N (g) + O₂ (g) → NO (g) ΔH = 90 kJ/mol
N (g) + O₂ (g) → NO₂ (g) ΔH = 34 kJ/mol
The required chemical reaction is given as follows;
2NO (g) + O₂ (g) → 2NO₂ (g)
Therefore, the heat of formation of 2 moles of NO = 2 × 90 = 180 kJ
The heat of formation of 2 moles of NO₂ = 2 × 34 = 68 kJ
Hence, given that the heat of formation of O₂ at room temperature = 0 kJ/mol, we have;
Change in enthalpy of the chemical reaction = Heat of formation of the products - Heat of formation of the reactants
Change in enthalpy of the chemical reaction = 68 kJ - 180 kJ = -112 kJ
Change in enthalpy of the chemical reaction = -112 kJ.
