Determine the heat of decomposition for this process

Question

Determine the heat of decomposition for this process at constant pressure and 25°C. (Look up the standard enthalpy of formation of the reactant and products in the table: ΔH°_f (BaCO₃(s)) =-1218.8 kJ/mol, ΔH°_f(BaO(s)) = -558.2 kJ/mol and ΔH°_f(Na₂CO₃(s)) = -1130.9 kJ/mol,ΔH°_f (Na₂O(s)) =-415.89 kJ/mol.)

Na₂CO₃(s) →Na₂O(s) + CO₂(g)