A person's blood alcohol (C2H5OH) level can be determined by titrating a sample of blood plasma with a potassium dichromate solution. The balanced equation is
16 H+(aq) + 2 Cr2O72-(aq) + C2H5OH(aq) 4 Cr3+(aq) + 2 CO2(g) + 11 H2O(l)
If 30.50 mL of 0.05905 M Cr2O72- is required to titrate 28.81 g plasma, what is the mass percent of alcohol in the blood?