Consider the system below at equilibrium at 200oC. 2Cl2 (g) + 2H2O (g) + heat ↔ 4HCl (g) + O2 (g) Which response contains all the stresses listed that will result in a shift of equilibrium so that more HCl is produced when equilibrium is re-established, and no stresses that will not? I. adding some Cl2 II. raising the temperature at constant pressure III. decreasing the volume at constant temperature

Based on Le Châtelier's principle, when a system in equilibrium change a condition, the system will produce a reaction in order to subtract the effect of the initial change.

For the equilibrium:

2Cl2 (g) + 2H2O (g) + heat ↔ 4HCl (g) + O2 (g)

I. Adding some Cl₂. Will produce the equilibrium shifts to the right in order to decrease the concentration of Cl₂ and produce more HCl.

II. raising the temperature at constant pressure. As the system requires heat to produce the reaction, the system will shift to the right in order to decrease the heat and produce more HCl

III. decreasing the volume at constant temperature. As the volume decreases, the pressure increases. In the left, there are 4 moles of gas and in the right there are 5. When the pressure increases the system will try to decrease the moles of gas in order to decrease the pressure. THat means the system will shift to the left in order to produce more Cl₂