HARD
JEE Main/Advance
IMPORTANT
Earn 100

One g of impure sodium carbonate is dissolved in water and the solution is made up to 250 mL. To 50 mL of this made up solution, 50 mL of 0.1 N-HCl is added and the mix after shaking well required 10 mL of 0.16 N-NaOH solution for complete titration. Calculate the % purity of the sample.

Important Questions on Redox Reactions

MEDIUM
JEE Main/Advance
IMPORTANT
50 mL of an aqueous solution of H2O2 was reacted with excess of KI solution and dilute H2SO4. The liberated iodine required 20 mL 0.1 N Na2S2O3 solution of complete interaction. Calculate the concentration of H2O2 in gL1.
MEDIUM
JEE Main/Advance
IMPORTANT
Write Lewis structure of O2-  ion and find out oxidation state of each oxygen atom? What is the average oxidation state of oxygen in this ion?