Chromel is an alloy composed of nickel, iron and chromium. A 0.7176g sample of the alloy was dissolved in HNO3 and diluted to 250ml in a volumetric flask. A 50ml aliquot of this sample, treated with pyrophosphate to mask Fe and Cr, required 26.24ml of 0.05831 M EDTA to reach the endpoint. A second 60ml aliquot was treated with hexamethylenetetra to mask the Cr. Titrating with 0.05831M EDTA required 40.35ml to reach the end point. Finally, a third 60ml aliquot was treated with 50ml 0.05831 M EDTA and back titrated to the end point with 7.21ml of 0.07316M Cu2+. what are the weights of Ni, Fe and Cr in the alloy