What is the enthalpy of decomposition of Berthollet’s salt KClO3 = KCl + 3/2 O2?

What is the enthalpy of decomposition of Berthollet’s salt KClO3 = KCl + 3/2 O2? How much heat is released (or absorbed?) During the decomposition of 1 kg of KClO by this reaction?

Reaction equation: KClO3 = KCl + 3/2 O2
1) Let us find the enthalpy by the corollary from Hess’s law:
ΔН = (ΔН (KCl) + ΔН (O2)) – ΔН (KClO3)

Table values:
ΔН (KCl) = – 436.56
ΔН (О2) = 0
ΔН (KClO3) = – 389.1

ΔН (chemical r-ii) = (-436.56 + 3/2 * 0) – (-389.1) = -47.46 [kJ / mol]

2) Find the amount of heat
Because ΔН <0, Q = – ΔН, Q = 47,46 [kJ] – The amount of heat released during the decomposition of 1 mol of KClO3
n (KClO3) = m / M = 1000 / 122.5 = 8.16 [mol]
M (KClO3) = Ar (K) + Ar (Cl) + Ar (O) * 3 = 122.5 [g / mol]
q = Q * n (KClO3) = 47.46 * 8.16 = 387.27 [kJ]