Question

7. A small amount of CuSO4*5H20 (0.973 g) was dissolved in 100.0 mL of water, When a 10.0 mL aliquot was titrated with EDTA, the endpoint was reached at 38.05 mL. A 10.0 mL aliquot of a 100.00 mL sample of unknown copper solution was also titrated with the same solution of EDTA. The endpoint was reached at 35.23 mL. What is the mass of Cu?' in the unknown solution?

Answer 1

Date Ans Molecular weight of Case Sho= 249 g most s moles: Mass 0.973-0.00390 Molar Mass 249 0.00390 Moles are broent in low ml. No of Moles gl yn lom l = 0.00390 - 0.000390 Molarity of Soln = 0.0039. 1000 = 0.039.M - 10 dority of Sou Too - MV, = M₂ V₂ 10-0390 x 10 = M, X38.05. Molarity g EDTA- My = 0.0390 xlo zoololm 38.05 for unknown a Volume o EPTA wed - 35:23ml Ho g mill moles of EOTA ured = 0.0102x35-23 = 0:361_ for loom , No of Mill Miles used: 0:36 X10 2361 . So Ne g Mill Moles of Cept = 3:41 Max of Cult in unknown 23-41x625=299.3 mg - 5229.23 mg = 0.229 gram