Consider the following reaction at equilibrium: 2NH3 (g) N2 (g) + 3H2 (g) Le Châtelier's principle predicts that the moles of H2 in the reaction container will increase with . Consider the following reaction at equilibrium: 2NH3 (g) N2 (g) + 3H2 (g) Le Châtelier's principle predicts that the moles of in the reaction container will increase with . an increase in total pressure by the addition of helium gas (V and T constant) a decrease in the total pressure (T constant) some removal of NH3 from the reaction vessel (V and T constant) addition of some N2 to the reaction vessel (V and T constant) a decrease in the total volume of the reaction vessel (T constant)

Le Châtelier's principle predicts that the moles of H2 in the reaction container will increase with a decrease in the total volume of the reaction vessel.
According to the Le Chatelier's principle, when a chnage is a applied to a system at equilibrium, then the equilibrium will shift in a way that counteracts the effect causing it.
In this case, a decrease in volume means there is an increase in pressure, therefore the equilibrium will shift towards the side with the fewer number of moles of gas.