The K_(sp) values of Al(OH)_(3) and 1.8 xx 10^(-14) respectively at room temp. If a salt contains equal concentration of Al^(+3) and Zn^(+2) ions, the ion first precipitated by adding NH_(4)OH is ?

The K_(sp) values of Al(OH)_(3) and 1.8 xx 10^(-14) respectively at ro

1.	The K_(sp) values of Al(OH)_(3) and 1.8 xx 10^(-14) respectively at room temp. If a salt contains equal concentration of Al^(+3) and Zn^(+2) ions, the ion first precipitated by adding NH_(4)OH is ?
Answer» `Zn^(+2)` `Al^(+3)` both starts precipitation at same time no ion precipitates Solution :`K_(SP)` of `Al(OH)_(3) = 8.5 xx 10^(-23)` `K_(sp)` of `Zn(OH)_(2) = 1.8 xx 10^(-4)` `Al(OH)_(3) hArr Al^(+3) + 3OH^(-)` `Zn(OH)_(2) hArr Zn^(+2)+2OH^(-)` `K_(IP) = [Al^(+3)][OH^(-)]^3` `K_(IP) = [Zn^(+2)][OH^(-)]^2` If `[Al^(+3)]=[Zn^(+2)] = 10^(-1)` `[Zn^(+2)][OH^(-)]^(2) gt 1.8 xx 10^(-14)` `[Al^(+3)][OH^(-)]^(3) gt 8.5 xx 10^(-23)` `[OH^(-)]^(2) gt 18xx10^(-14),[OH^(-)]^(3)gt9.4xx10^(-8)` `[OH^(-)]gt4.2xx10^(-7)`