Question 17N.1.sl.TZ0.14

The enthalpy changes for two reactions are given.

Br₂ (l) + F₂ (g) → 2BrF (g)         ΔH = x kJ
Br₂ (l) + 3F₂ (g) → 2BrF₃ (g)      ΔH = y kJ

What is the enthalpy change for the following reaction?

BrF (g) + F₂ (g) → BrF₃ (g)

A.  x – y

B.  –x + y

C.  $\frac{1}{2}$(–x + y)

D.  $\frac{1}{2}$(x – y)