Question

`Ni+H_(2)SO_(4)` (hot and concentrated) `to X(g)`
The liberated gas (select the correct statement)
A. develops blue colour spots on the filter paper moistened with potassium iodate and strach solution
B. turns acidified `K_(2)Cr_(2)O_(7)` solution green
C. produces black precipitate with lead acetate solution
D. reacts with `Cl_(2)` water to produce an acid which gives white fumes with ammonia.

Answer 1

Correct Answer - A,B,D
(A)`5SO_(2)+2IO_(3)^(-)+4H_(2)O to I_(2)+5SO_(4)^(2-)+8H^(+) , I_(2)+` starch `to` blue colour.
(B)`2H^(+)+3SO_(2)+Cr_(2)O_(7)^(2-) to 2Cr^(3+) ("green")+3SO_(4)^(2-) +H_(2)O`
( C)`Pb^(2+)+SO_(3)^(2-) to PbSO_(3) darr `(white)
(D)`SO_(2)+2H_(2)O +CI_(2) to H_(2)SO_(4) + HCl`
`HCl+NH_(3) to NH_(4)Cl`
`NI+H_(2)SO_(4) +2H^(+) to Ni^(2+) +SO_(2) uarr [X] + 2H_(2)O`
With dilute `H_(2)SO_(4)`, hydrogen gas is liberated.