Calculate enthalpy for the reaction ClF + F2 → CIF3 using the following three reactions.
1) 2ClF + O2 → Cl2O + F2O, ∆H1 = 167.4 kJ
2) 2ClF3 +202 → Cl2O + 3F2O, ∆H2 = 341.4 kJ
3) 2F2 + O2 → 2F2O, ∆H3 = -43.4 kJ ∆Hrxn = [ ? ] kJ
Enter either a + or - sign AND the magnitude. Use significant figures.

pls help urgent :-(