The nitride salt of Ca when treated with `H_2O` gives

Mg on heating to redness in an atmosphere of N_2 and then on treating with H_2O gives:

A soldium salt of unknown anion when treated with MgCl_(2) gives white precipitate only on boiling. The anion is:

A sodium salt of unknown anion when treated with MgCl_(2) gives a white ppt . On boiling. The anion is

A sodium salt of unknown anion when treated with MgCl_(2) gives a white ppt . On boiling. The anion is

A soldium salt of unknown anion when treated with MgCl_(2) gives white precipitate only on boiling. The anion is: