What are different ways to express Avogadro's Number?

Consider the reaction: n2(g) + o2(g) ⇄ 2no(g) kc = 0.10 at 2000oc starting with initial concentrations of 0.040 mol/l of n2 and 0.040 mol/l of o2, calculate the equilibrium concentration of no in mol/l how would this be done?

How does the presence of oxygen affect the chemical pathways used to extract energy from glucose?

Which change to the system wood cause the freely-moving piston to lower?