vetchem

I think it's the wording of the question that has me so hung up on this question... A 200 mL NaOH solution was added to 400 mL of a 2.00 M HNO2 (Ka = 4.5 x 10-4). The pH of the resulting solution was 1.5 units greater than that of the original acid solution. Calculate the molarity of the NaOH solution. Can someone help?

I'm working on a homework problem, and the question is so vague I'm not sure how to answer it. The reaction quotient for a gas phase reaction has a value of 2000. If the number of moles of reactants in the reaction equation is equal to that of the products, which of the following statements is true? a. the reaction must proceed to the left to establish equilibrium b. the reaction must proceed to the right to establish equilibrium c. when the system is at eq., the concentrations of the products will be much larger than the concentrations of the reactants d. the concentrations of the products are generall larger than the concentrations of the reactants, e. none of the above is true. can i answer this without knowing Kc?