Saved Bookmarks
| 1. |
Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydroxides) two ores [X] and [Y] show the following reactivity. (i)[X] on calcination gives a black solid (S), carbon dioxide and water. (ii)[X] Dissolved in dilute HCl, on reaction with Kl gives a white precipitate (P) and iodine. (iii)[Y] on roasting gives metal (M) and a gas `(G_(1))` which turns acidified `K_2Cr_2O_7` solution green. (iv)[Y] on reaction with dil.HCl gives a white precipitate (Q) and another gas `(G_2)` which turns lead acetate solution black, and also reacts with gas `(G_1)` to precipitate colloidal sulphur in presence of moisture. Reaction involved: (i)`CuCO_3. Cu(OH)_2oversetDeltatoCuOdarr("black")+CO_2+H_2O` `CuCO_3.Cu(OH)_2+4HCl to2CuCl_2+3H_2O+CO_2` (ii)`2Cu^(2+)+4I^(-)toCu_2l^2 darr (P)("white")+l_2uarr` (iii)`2Cu_2S+3O_2to2Cu_2O+2SO_2(G_1)` `Cu_2S+2Cu_2Oto6Cu+SO_2` (iv)`Cu_2S+2HCl to 2CuCldarr(Q)("white")+H_2S(G_2)` `Pb^(2+)+H_2StoPbSdarr("black")+2H^(+)` (v)`SO_2(G_1)+2H_2S(G_2)overset("moisture")to3Sdarr+2H_2O` The white precipitate (P) is of :A. `Cu_2I_2`B. `Cu I_2`C. `K_2[Cu l_4]`D. None |
|
Answer» Correct Answer - A `CuCO_3+2HCl to CuCl_2+CO_2 +H_2O , CuCl_2 + 2KltoCu l_2 + 2KCl , 2Cu l_2 to Cu_2l_2 darr (P) +I_2` |
|