In the equilibrium 2HI ⇌ H2 + I2, what occurs if no shift happens when pressure increases?

In the equilibrium reaction 2HI ⇌ H2 + I2, if there is no shift in the equilibrium position when the pressure is increased, it indicates that the number of gaseous molecules on both sides of the equilibrium is equal.

In this reaction, the left side consists of 2 molecules of HI, while the right side has 1 molecule of H2 and 1 molecule of I2, totaling 2 molecules as well. Since the total number of gaseous molecules is the same on both sides (2 on each side), an increase in pressure will not influence the equilibrium position according to Le Chatelier's Principle. This principle states that a change in pressure will shift the equilibrium towards the side with fewer gas molecules, but because both sides contain the same number of molecules, there is no effect on the position of equilibrium under pressure change.

Thus, the correct conclusion that can be drawn from the scenario is that the number of gaseous molecules is equal on both sides of the reaction.