Match the effects on the concentration of SO2 gas when the following changes occur after initial equilibrium has been established in this system:

2SO2 (g) + O2 (g) 2SO3 (g) + 46.8 kcal

pressure increases: increase/decrease/no change

increase [O2] : no change/increase/decrease

increase volume of chamber: increase/no change/decrease

adding a catalyst:no change/decrease/increase

raising the temperature: increase/decrease/no change

Using Le Chateliers principle: the equilibrium will want to counteract any changes made to it. If pressure increases, the equilibrium will shift to the right as there is less particles on that side, decreasing SO2 conc. An increase of O2 will push the reaction towards the right, also decreasing SO2 conc. Increasing the volume of chamber is decreasing the pressure and therefore more SO2 will form. A catalyst drives the reaction to the right and therefore reduces SO2 levels. Raising temperature will drive the reaction to the left side as the reaction is exothermic, therefore increasing SO2 levels.