A sample of a chromium-containing alloy weighing 3.450 g was dissolved in acid, and all the chromium in the sample was oxidized to CrO4 2-. It was then found that 3.18 g of Na2SO3 was required to reduce the CrO4 2- to CrO2 - in a basic solution, with the SO3 2- being oxidized to SO4 2-.
(a) Write a balanced equation for the reaction f CrO4 2- with SO3 2- in a basic solution.
(b) How many grams of chromium were in the alloy sample?
(c) What was the percentage by mass of chromium in the alloy?