Barium carbonate, baco3, is stable at ambient temperatures, but decomposes to barium oxide and carbon dioxide at higher temperatures. baco3(s) bao(s) + co2(g) at a certain temperature, this system is in equilibrium in a closed system and contains appreciable amounts of all three compounds. which changes will lead to an increase in the pressure of co2 present at equilibrium? i. adding more baco3(s) ii. increasing the volume of the container