Question

How many of the following salts give precipitate with aq. NaOH solution which dissolve in excess of the reagent?
`CdSO_(4), Pb(NO_(3))_(2), CrCI_(3). MnCI_(2). ZnSO_(4). CuSO_(4). Bi(NO_(3))_(3), SnCI_(4)`

Answer 1

Correct Answer - 4
`Pb(NO_(3))_(2), CrCl_(3), ZnSO_(4)` and `SnCl_(4)`
`Pb(NO_(3))_(2) +2NaOHrarrunderset("White ppt")(Pb(OH))_(2)+2NaNO_(3)`
`Pb(OH)_(2) + 2NaOH rarr Na_(2)PbO_(2)+2H_(2)O`
`CrCl_(3)+3NaOH rarr underset("Green ppt")(Cr((OH)_(3))+3NaCl`
`Cr(OH)_(3)+NaOH rarr NaCrO_(2)+2H_(2)O`
`ZnSO_(4)+2NaOH rarr underset("White ppt")(Zn((OH)_(2))+Na_(2)SO_(4)`
`Zn(OH)_(2)+2NaOH rarrNaZnO_(2)+2H_(2)O`
`SnCl_(4)+4NaOH rarr underset("White ppt")(Sn(OH)_(4))+4NaCl`
`Sn(OH)_(4)+2NaOH rarr Na_(2)SnO_(3)+3H_(2)O`