25.0 cm^(3) of an aqueous solution of H_(2)O was treated with excess of KI soluiton in acidic medium and the liberated iodine required 10.0 cm^(3) of 0.01 M thiosuphte solutoin find out the concentratin of H_(2)O_(2) in gramsper litre ?

25.0 cm^(3) of an aqueous solution of H_(2)O was treated with excess o

1.	25.0 cm^(3) of an aqueous solution of H_(2)O was treated with excess of KI soluiton in acidic medium and the liberated iodine required 10.0 cm^(3) of 0.01 M thiosuphte solutoin find out the concentratin of H_(2)O_(2) in gramsper litre ?
Answer» Solution :STEP 1 To write the balanced chemical equation of the redox reaction `2KI + H_(2)SO_(4)+H_(2)O rarr K_(2)SO_(4)+I_(2)+H_(2)O` `2Na_(2)S_(2)O_(3)+I_(2)rarrNa_(2)S_(4)O_(6)+2Nal` `2KI+H_(2)SO_(4)+2 Na_(2)S_(2)O_(3)+H_(2)O_(2)rarrK_(2)SO_(4)+Na_(2)S_(4)O_(6)+2 Nal + 2 H_(2)O` From the above equation Step 2 To FIND out hte concentration fo `HH_(2)O_(2)` Let the molarity f `H_(2)O_(2)` solution =`M_(1)` Applying molarity equaition `(M_(1)xx25)/(1)=(10xx0.1)/(2)M_(1)=(10xx0.1)/(2xx25)=0.02M` Mol wt of `H_(2)O_(2)=2xx1+2xx16=34` `therefore` concentration of `H_(2)O_(2)=0.02xx34 =0.68 g L^(-1)`