What happens to the concentration of
NO(g) when the total pressure on the equilibrium reaction
3NO2(g) + H2O <---> 2HNO3(aq) + NO(g)
is increased (by compression)?
1. increases
2. remains the same
3. decreases
4. Unable to determine
It increases.
In a gaseous equilibrium (I assume the H2O is liquid) increases pressure shifts the equilibrium to the side with fewer mols of gas.
To determine the effect of increasing the total pressure on the equilibrium reaction, we need to consider Le Chatelier's principle. According to this principle, when a system at equilibrium is subjected to a stress, it will shift in the direction that minimizes the effect of the stress.
In this case, increasing the total pressure would be considered a stress. The total pressure can be increased by compression, which means reducing the volume of the system or adding more reactants or products. Since the number of moles of gases on the reactant side (3NO2(g) + H2O) is greater than on the product side (2HNO3(aq) + NO(g)), compressing the system would increase the total pressure.
To minimize the effect of the increased pressure, the system would shift in the direction that reduces the total number of gas moles. By Le Chatelier's principle, the equilibrium would shift towards the side with fewer moles of gas, which in this case is the product side (2HNO3(aq) + NO(g)). As a result, the concentration of the product NO(g) would decrease.
Therefore, the answer is:
3. decreases