(i)Though Mg(OH)_2 is insoluble, Mg^2+ does not get precipitated in the group III. Explains(ii)When a chloride salt is heated with conc. H_2SO_4 Het gas is erelved whereas when a bromide salt is heated with conc. H_2SO_4, Bi gas is evolved. Why?

(i)Though Mg(OH)_2 is insoluble, Mg^2+ does not get precipitated in th

1.	(i)Though Mg(OH)_2 is insoluble, Mg^2+ does not get precipitated in the group III. Explains(ii)When a chloride salt is heated with conc. H_2SO_4 Het gas is erelved whereas when a bromide salt is heated with conc. H_2SO_4, Bi gas is evolved. Why?
Answer» Solution :(i)The group III ragent is saturated `NH_4Cl` and `NH_4OH`.`NH_4Cl` being a STRONG eletrolyte DISSOCIATE completely and supresses the dissociation of the weak electrolyte `NH_4OH` HENCE the concentration Of OHis reduced and is insuuficent to overcome the Higher `K_spofMg(OH)_2` <BR>(ii)`Cl^(-)H_2SO_4to HCl+HSO_4` `In the case of abromide salt HBr formed is a reducing agent CONC. `H_2SO_4`oxidation the HBr to `Br_2` `Br^(-)+H_2SO_4toHBr+H_2SO_4` `2HBr+ H_2SO_4toBR_2uarr+SO_2+2H_2O`