An inorganic Lewis acid `(X)` shows the following reactions :
(a) It fumes in moist air.
(b) The intensity of fumes increase when a rod dippod in `NH_(4) OH` is brought near it.
( c) To an aqueous solution of `(X)`, addition of `NH_(4)Cl` and `NH_(4)OH` gives a precipitate which dissolves in `NaOH` solution.
(d) An acidic solution of `(X)` does not give a precipitate with `H_(2) S`.
Identify `(X)` and gives chemical reactions for `(a)` to `(d)`.

Options

A. `FeCI_(3)`
B. `AICI_(3)`
C. `SnCI_(2)`
D. `ZnCI_(2)`

Answer

b

Explanation

`(X)` is `AICI_(3)`
`underset("Mostone")(AICI_(3)) + 3H_(2)O rarr AI(OH)_(3) darr + underset(("Fumes"))(3HCI) `
`AICI_(3)+3NH_(4)OH rarr AI(OH)_(3) darr + 3NH_(4)CI`
`AI(OH)_(3) + NaOH rarr NaAIO_(2) + 2H_(2)O`
`AICI_(3) + H_(2)S + H^(o+) rarr` No ppt