Q5. A sample of calcium chloride was dissolved in water and excess oxalic acid added. The precipitated calcium oxalate was filtered off and re-dissolved in sulfuric acid. The resulting solution was titrated with potassium permanganate, 0.002 mol being required. Estimate the number of moles of calcium chloride present in the original sample. CaCl2 + (COOH)2 Ca(COO)2 + 2 H+ 2 cr Ca(COO)2 + H2SO4 = Ca2+ + S0,2- +(COOH)2 5 (COOH)2 + 2 MnO4 +6 H = 2 Mn2+ + 10 CO, +8 H2O + Hint: First decide which are the intermediates