The reaction between flourine and bromide is reversible and thus a chemical equilibrium is established?

LeChat states that a system in equilibrium will react to reduce the effect of the stress placed upon it

For the reaction      F2  +  Br2    ->  2 FBr

*increasing pressure will not change the equilibrium yield, since both sides of the reaction have an equal number of molecules, and so will be affected equally. If one side had fewer molecules, it would shift towards that to reduce volume and thereby, pressure

*increasing the temperature will probably shift the equilibrium to the right, increasing the amount of products; the bromine and fluorine molecules will move more rapidly and collide with with sufficient energy to acheive activation energy
*if the reaction is endothermic, the equilibrium will definitely shift to increase products as the system tries to use up the added heat energy

*adding a catalyst does not affect the equilibrium position, since both reactions are affected equally; the system will, however, acheive equilbrium more quickly