Calculate the enthalpy of reaction.

D + F --> G + M
using the following equations and data:
G + C --> A + B ΔH = +277 kJ
C + F --> A ΔH = +303 kJ
D  B --> M ΔH = -158 kJ

To calculate the enthalpy of reaction for the given equation D + F --> G + M, we need to determine the sum of the enthalpy changes for the individual steps involved in the reaction.

Step 1: G + C --> A + B ΔH = +277 kJ (Equation 1)
Step 2: C + F --> A ΔH = +303 kJ (Equation 2)
Step 3: D  B --> M ΔH = -158 kJ (Equation 3)

We need to manipulate these equations to match the overall reaction equation. Since G and M are on the right side of the equation, we need to reverse the equation in step 1 and step 3.

Revised step 1: A + B --> G + C ΔH = -277 kJ
Revised step 3: M --> B  D ΔH = +158 kJ

Now, we can add up the revised steps to obtain the overall equation:

Step 1 + Step 2 + Step 3:
(A + B --> G + C) + (C + F --> A) + (M --> B  D) = (A + B + C + F + M --> G + D)

Since step 2 does not involve M, we will exclude it from the overall equation.

Now, we add up the enthalpy changes for the revised steps:
ΔH_total = (-277 kJ) + (+303 kJ) + (+158 kJ) = +184 kJ

Therefore, the enthalpy of reaction for D + F --> G + M is +184 kJ.