A 25 ml solution of unkown containing Fe+3 and Ca+2 required 16.06 ml of 0.051 M EDTA for complete the reaction. A 50 ml of the same of the unkown was treated with NH4F to protect Fe+3. then the Ca+2 was reduced and masked by addition thiourea. upon addition of 25 ml of 0.051 M EDTA, the Fe+3 was liberated fron its floride complex and formed EDTA complex . the excess ETDA required 19.77 ml of 0.01883 M pb+2 to reach the end point by using xylenol orange indicator. Find the concentarion of Ca+2 in the unkown sample?

A 25 ml solution of unkown containing Fe+3 and Ca+2 required 16.06 ml of 0.051 M EDTA for complete the reaction. A 50 ml of the same of the unkown was treated with NH4F to protect Fe+3. then the Ca+2 was reduced and masked by addition thiourea. upon addition of 25 ml of 0.051 M EDTA, the Fe+3 was liberated fron its floride complex and formed EDTA complex . the excess ETDA required 19.77 ml of 0.01883 M pb+2 to reach the end point by using xylenol orange indicator. Find the concentarion of Ca+2 in the unkown sample?

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter31: Introduction To Analytical Separations

Section: Chapter Questions

Problem 31.32QAP

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