Answer:
a. Spontaneity for the forward reaction.
b. No change
Step-by-step explanation:
According to LeChatelier´s principle a system in equilibrium will react in such a way as to relieve the stress on the equilibrim.
In part a we will observe that the spontaneity for the forward reaction in order to decrease the stress by to consuming part of the NO2 added.
In part b No change since N2O is neither a reactant or a product. However, if N2O were present ( information which is absent in the question ) although not being a reactant or product, its removal will have the effect of decreasing the total pressure on the equilibrium and it will decrease the spontaneity of the forward reaction such as to relieve the decrease the stress favoring the reactant side which has 2 mol gas vs 1 mol gas in product, hence more pressure.