Lechatelier's Principle

When more reactant is added into a reaction system at equilibrium, the system reacts by shifting the equilibrium position to the right in order to counteract the increase in reactant concentration. This results in the formation of more product to restore equilibrium.

When the pressure on a gaseous reaction system at equilibrium is increased, the equilibrium will shift in favor of the side with the least gas molecules. This is because increasing the pressure will cause the system to try to reduce the number of gas molecules in order to decrease the pressure. Therefore, the equilibrium will shift towards the side with fewer gas molecules to achieve a new equilibrium with a lower pressure.

When oxygen gas is removed from the reaction, the equilibrium will shift to the right in order to replace the lost oxygen. This is because the reaction wants to maintain a balance of reactants and products. By shifting to the right, more H2 and O2 will be produced, which will increase the concentration of oxygen gas in the system. This shift to the right will help restore the equilibrium and compensate for the removal of oxygen gas.

The reaction given is an example of a reversible reaction, where the reactants N2O4(g) and NO2(g) can interconvert. At equilibrium, the forward and backward reactions occur at equal rates. In this reaction system, N2O4 is colorless and NO2 is brown. When the volume is decreased, according to Le Chatelier's principle, the equilibrium will shift in the direction that reduces the number of gas molecules. Since the forward reaction produces two moles of gas (2 NO2), decreasing the volume will shift the equilibrium to the left, favoring the reverse reaction and causing the colorless N2O4 to dominate. Therefore, the mixture will become colorless.

An increase in volume will cause the reaction equilibrium to shift in favor of the products. According to Le Chatelier's principle, when the volume of a system is increased, the equilibrium will shift in the direction that produces fewer moles of gas. In this reaction, the reactants have one mole of gas (H2), while the products have two moles of gas (H2 and O2). Therefore, an increase in volume will favor the side with fewer moles of gas, which is the products.

The reaction is endothermic. According to Le Chatelier's Principle, increasing the temperature of an endothermic reaction will favor the endothermic direction. Thus, the equilibrium will shift to the right. Therefore, the correct answer is: It will shift to the right.