A polyvalent metal weghing 0.1 g and having atomic weight 51 reacted will dil H_2SO_4 to give 43.9 " mL of " H_2 at STP. This solution containing the metal in the lower oxidation state was found to require 58.8 " mL of " 0.1 permanganate for complete oxidation. What are the valencies of the metal.

A polyvalent metal weghing 0.1 g and having atomic weight 51 reacted w

1.	A polyvalent metal weghing 0.1 g and having atomic weight 51 reacted will dil H_2SO_4 to give 43.9 " mL of " H_2 at STP. This solution containing the metal in the lower oxidation state was found to require 58.8 " mL of " 0.1 permanganate for complete oxidation. What are the valencies of the metal.
Answer» Solution :Suppose the lower oxidationnumber of the metal is X . GIVEN that : ` {:("metal "+,H_(2)SO_(4) to ,H_(2)),(0.1 g ,,43.9 " mL at STP"),((0.1)/(51//X)EQ,,(43.9)/(11200)eq):}` (eq . Wt. of the metal= `51/X ` and volume occupied by 1 eq. of hydrogen at NTP = 11200 mL ) Now , eq. of the metal = eq. of hydrogen `(0.1)/(51//X) = (43.9)/(11200 ) , X = 2 ` Further, the metalis CHANGING from lower OXIDATION number 2 to higher oxidation number , say , Y . ` :. ` eq. wt of the metal ` = 51/(" change in ON") = 51/(Y-2)` Eq. of metal = eq. of `KMnO_(4)` ` = (" m.e of " KMnO_(4))/(1000)` ` :. "" (0.1)/(51/(Y-2)) = (0.1 xx 58.8)/1000` ` :. "" Y = 5 ` .