A mixture of two gases, H_(2)S and SO_(2) is passes throgh three beakers successivly. The first beaker contains Pb^(2+) ions, which absobs all H_(2)S to form PbS. The second beaker contains 25mL of 0.0396 N I_(2). Whichocidises all SO_(2) to SO_(4)^(2-) . The thirdbeaker contains 10 mL of 0.0345 N thisulphate solutionti retainany I_(2) carried over from the second absorber. Thesolution from first absorber was made acidic and treated with 20 mL of 0.0066 M K_(2) Cr_(2) O_(7), acidic and treated with 20mL of 0.006M K_(2) Cr_(2)O_(7) which convertedS^(2-) to SO_(2). The excess dichromate was reacted with solid KIand the liberated iodine required 7.45mL of 0.0345N Na_(2)S_(2)O_(3) solution. The solution in the second andthrid absorbers were combined and the resulatantiodide was treated with 2.44 mL fo the same solution of thisulphate. Calculate the conventrations fo SO_(2) and H_(2)S in (mg)/"litre"of the sample.