Calculate the masses of magnesium and calcium contained in 100.00 ml of a solution of the salts of these metals, if 20.28 ml is consumed when titrating 10.00 ml of this solution with 0.05000 M EDTA solution with the eryochrome black T indicator in the presence of ammonia buffer solution. EDTA solution, and titrated with murexide after adding 2 N. sodium hydroxide solution went to 12.89 ml EDTA solution of the same concentration