In which of the following oxidation state of phosphours is + 3?


Correct option is

Phosphours acid

In phosphours acid (H3PO3) oxidation state is +3. In orthophosphoric acid (H3PO4), it is +5. In metaphosphoric acid (HPO3), it is + 5. In prophosphoric acid (H4P2O7), it is +5.



KMnO4 oxidizes Xn+ into,  itself changing to Mn2+ in acid solution. 2.68 × 10–3 mol of Xn+ require  mol of KMnO4. The value of n is


To 1 mole of pyrophosphoric acid (H4P2O7) in aqueous solution 2 mole of NaOH are added. The salt formed is


What volume of 0.01 M K2Cr2O7 would be required to oxidize Fe (II) in 50ml of 0.03 M solution of ferrous ammonium sulphate in acidic medium?


100ml of 0.01 M KMnO4 oxidizes 10ml of H2O2 sample in acidic medium. The volume strength of H2O2 sample is


A sample of mixture of AO and A2O3 in 2 : 1 molar ratio takes 0.015 mole of K2Cr2O7 to oxidize the sample completely to from  in acidic solution. Millimoles of AO and A2O3 in the sample are respectively


0.01 mole of Fe3O4 is treated with excess of KI solution in presence of dilute H2SO4 whereby iron is reduced to Fe2+ along with liberation of iodine. What volume of 0.1 M Na2S2O3 will be needed to reduce the librated iodine?


In which of the following reaction, oxidation number of N remains unchanged?



KMnO4 acts as a strong oxidizing agent in acidic medium. The reaction that occurs is

What will be the effect on the electrode potential of a half-cell represented as  if the concentration of H+ ion is doubled in solution?


Determine the volume of M/8 KmnO4 solution required to react completely with 25.0 cm3 of M/4 FeSO4 solution is acidic medium.


Calculate the concentration of hypo (Na2S2O3.5H­2O) solution in g dm–3 if 10.0 of this solution decolourised 15 mL of M/40 iodine solution.