Given
a. `NH_(3)(g)+3CI_(2)(g)rarr NCI_(3)(g)+3HCI(g),DeltaH_(1)`
b. `N_(2)(g)+3H_(2)(g)rarr 2NH_(3)(g),DeltaH_(2)`
c. `H_(2)(g)+CI_(2)(g)rarr 2HCI(g),DeltaH_(3)`
Express the enthalpy of formation of `NCI_(3)(g)(Delta_(f)H^(Theta))` in terms of `DeltaH_(1), DeltaH_(2)`,and `DeltaH_(3)`.
A. `DeltaH_(f)=-DeltaH_(1)+(DeltaH_(2))/(2)-(3)/(2)DeltaH_(3)`
B. `DeltaH_(f)=DeltaH_(1)+(DeltaH_(2))/(2)-(3)/(2)DeltaH_(3)`
C. `DeltaH_(f)=DeltaH_(1)-(DeltaH_(2))/(2)-(3)/(2)DeltaH_(3)`
D. None