Problem- i). An iron ore is analyzed for iron content by dissolving in acid, converting the iron to Fe2+, and then titrating with standard 0.0150 M K2Cr2O7 solution. If 35.6 mL is required to titrate the iron in a 1.68 g sample, how much Fe2+ is in the sample? What is the weight percent of Fe2O3 in the sample (assuming all the iron is in this form)? The titration reaction is: 6 Fe2+ + Cr2O72- + 14 H+ --> 6 Fe3+ + 2 Cr3+ + 7 H2O.

ii).Calculate the grams of each substance required to prepare each the following solutions:

1. 500.0 mL of 0.100 M Na2SO4

2. 250.0 mL of 0.250 M Fe(NH4)2(SO4)2?6H2O

3. 100.0 mL of 0.667 M Ca(C9H6ON)2

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