3. a) Write all equilibrium expressions, the electroneutrality condition, and the mass balance, for the addition of 50 mg NH4Cl to 2-L of water. Show the magnitudes of any constants. b) What would the concentration of Cl- be? 4. Write all equilibrium expressions, the electroneutrality condition, and the mass balance, for the addition of 50 mL 1 M Na 2CO3 to 10 L of water. Show the magnitudes of any constants, including the concentration of Na+