The molar concentration of the ions in the form moles/liter is provided for the given solutions.

A solution of ammonium sulfate (NH4)2SO4 with a concentration 0.15 M has a NH4 ion concentration of 0.15*2 = 0.3 M and the concentration of SO4 ions is 0.15 M

30 gm of CaBr2 is equivalent to 0.15 moles of CaBr2. Dissolved in 0.15 liters of water, the concentration of Ca ions is 1 M and the concentration of Br ions is 2 M

When 200 ml of 0.12 M NaCl is added to 300 ml of 0.1 M Na2SO4, the concentration of Na ions in the resulting mixture is 0.168 M, the concentration of Cl ions is 0.048 M and the concentration of SO4 ions is 0.06 M.