Discussion Forum



1)

An aqueous solution of a mixture of two inorganic salts, when treated with dilute HCl, gave a precipitate (P) and filtrate (Q). The precipitate  P was found to dissolve in hot water. The filtrate (Q) remained unchanged when treated with H2 S in a dilute mineral acid medium. However, it gave a precipitate (R)   with H2 S  in an ammonical medium.The precipitate R gave a coloured solution (S) when treated with H2O2 in an aqueous NaOH medium.

The coloured solution S contains


A) $Fe_{2}(SO_{4})_{3}$

B) $CuSO_{4}$

C) $ZnSO_{4}$

D) $Na_{2}CrO_{4}$

Answer:

Option D

Explanation:

Plan PbCl2 is soluble in hot water. In ammonical medium , cations of group III and IV may be precipitated as hydroxide or sulphide  and dissolved in H2O2 due to oxidation

Mixture of two inorganic salts

1252021758_c22.JPG

S is  $Na_{2}CrO_{4}$