An aqueous sample which is having 15.00-mL, was analyzed for its nitrite content by reaction with the 40.13 mL of 0.04013 N acidified potassium permanganate solution, liberating nitrate ion. The excess permanganate was measure by reaction with the 0.04013 N iron(II) solution, requiring 2.59 mL to reach equivalence. Calculate the g/L concentration of nitrite in the original sample.