Phosphating Chemicals

Take 10 ml of bath material and titrate against 0.1 N Sulphuric acid, using phenolphthalein as indicator. The pink end point should be between 60-65 ml. If found less add more Meproche 245. Every 0.8 kg of Meproche 245 per 1000 liters of barh material gives rise in pointage (No. of ml of 0.1 N sulphuric acid), hence maintain the pointage between 60 and