Oxidation number of sodium in sodium amalgam is


Correct option is


Sodium amalgam is a homogeneous mixture of Na and Hg and as such Na exists in the elemental state and hence its O.N. is zero.



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.


0.5 g of an impure sample of oxalate was dissolved in water and the solution made to 100 ml. On titration 10 ml of this solution required 15 ml of N/20 KMnO4 solution. Calculate the percentage of pure oxalate in the sample.


Predict whether zinc and silver react with 1 M sulphuric acid to give out hydrogen or not. Give that the standard potentials of zinc and silver are – 0.76 volt and +0.80 volt respectively.



Can a solution of 1 M copper sulphate be stored in a vessel made of nickel metal? Given that


or Is it possible to store copper soulphate solution in a nickel vessel?


0.2 of sample H2O2 reduced 20 ml of 0.1 M KMnO4 solution in acidic medium. What is the percentage purity of H2O2?


16.6 g of pure potassium iodide was dissolved in water and the solution was made up to one litre. V cm3 of this solution was acidified with 20 cm3of 2 M HCl. The resulting solution required 10 cm3 of decinormal KIO3for complete oxidation of I ions to ICl. Find out the value of V.


Both  (aq) can be used to titrate Fe2+ (aq). If in a given titratoion, 24.50 cm3 of 0.1 M  were used, then what volume of 0.1 M  solution would have been used for the same titration?


1.1 g of a sample of copper ore is dissolved and Cu2+ (aq) is treated with KI. The iodine thus liberated required 12.12 cm3 of 0.1 M Na2S2O3solution for titration. What is the percentage of copper in the ore?



In the given reaction,


X, Y, Z are