4. What is the H ion concentration in a 4.8 102 M KOH solution?* (1 Point) 4.8 10-2 M 1.0 - 10-7M 4.8 10-11M 4.8 10-12M 2.1 - 10-13M 5. The brown gas NO2 and the colorless gas N204 exist in equilibrium, In an experiment, 0.625 mole of N,O4 was introduced into a 5.00 L vessel and was allowed to decompose until equilibrium was reached. The concentration of N2O4 at equilibrium was 0.0750 M. Calculate Kc for the reaction. (1 Point) 2NO2 N204 () 0.050 0.0750 0.125 0.10 7.5