Given the following equations, determine the standard enthalpy of formation (
Δ
H
∘
f
) for
IF
(
g
)
.
I
2
(
g
)
+
F
2
(
g
)
⟶
2
IF
(
g
)
Δ
H
∘
298
=
−
254
kJ
I
2
(
s
)
⟶
I
2
(
g
)
Δ
H
∘
298
=
62
kJ