A chromite sample weighting 0.80 g is melted with sodium peroxide. The melt is leached with water, boiled and filtered to separate the iron in the form of hydrated oxide. Chromate-containing filtrate is neutralized with silver chromium precipitate as Ag2CrO4. The precipitate is washed, dissolved in nitric acid, and the silver precipitate is in the form of AgCl, weighing 0.3264 g. Calculate the many percent of a) Cr and b) Cr2O3 in the sample .