19. A black mineral A on heating in air gives a gas B. The mineral A on reaction with H2SO4 gives a gas C and a compound D. Bubbling C into an aqueous solution of B gives white turbidity. The aqueous solution of compound D, on exposure to air, with NH4SCN gives a red compound E. The compounds A and E respectively, are: A. PbS and Pb(SCN)2. B. NiS and Ni(SCN)2. C. FeS and Fe(SCN)3. D. CoS and Co(SCN)2.

19. A black mineral A on heating in air gives a gas B. The mineral A o

1.	19. A black mineral A on heating in air gives a gas B. The mineral A on reaction with H2SO4 gives a gas C and a compound D. Bubbling C into an aqueous solution of B gives white turbidity. The aqueous solution of compound D, on exposure to air, with NH4SCN gives a red compound E. The compounds A and E respectively, are: A. PbS and Pb(SCN)2. B. NiS and Ni(SCN)2. C. FeS and Fe(SCN)3. D. CoS and Co(SCN)2.
Answer» 19. A black mineral A on heating in air gives a gas B. The mineral A on reaction with H2SO4 gives a gas C and a compound D. Bubbling C into an aqueous solution of B gives white turbidity. The aqueous solution of compound D, on exposure to air, with NH4SCN gives a red compound E. The compounds A and E respectively, are: A. PbS and Pb(SCN)2. B. NiS and Ni(SCN)2. C. FeS and Fe(SCN)3. D. CoS and Co(SCN)2.