Answer:
The position of equilibrium will move to the right
Explanation:
[tex]\rm Fe_{3}O_{4}(g) + CO(g) \rightleftharpoons 3FeO(s) +CO_{2}(g); \Delta H^{\circ} = +35.9 \, kJ[/tex]
The enthalpy of reaction is positive, so the reaction is endothermic and we can consider the heat as a "reactant".
We can rewrite the equation as
[tex]\rm Fe_{3}O_{4}(g) + CO(g) +35.9 \, kJ \rightleftharpoons 3FeO(s) +CO_{2}(g)[/tex]
According to Le Châtelier's Principle, when a stress is applied to a system at equilibrium, the system will respond in a way that tends to relieve the stress.
In this problem, the stress is the increase in temperature (addition of heat).
If we add heat, the position of equilibrium will move to the right to get rid of the heat.