An aqueous solution contains 10% ammonia by mass and has a densityof 0.99 g cm^(-3) . Calculate hydroxyl and hydrogen ion concentration in this solution . K_(a)for NH_(4)^(+)=5.0xx10^(-10).

An aqueous solution contains 10% ammonia by mass and has a densityof 0

1.	An aqueous solution contains 10% ammonia by mass and has a densityof 0.99 g cm^(-3) . Calculate hydroxyl and hydrogen ion concentration in this solution . K_(a)for NH_(4)^(+)=5.0xx10^(-10).
Answer» Solution :10% ammonia by mass means 10 g `NH_(3)` are present in 100 g of the solution. `:.` Molarity of the solution `=(10)/(17) xx (1)/(100//0.99)xx1000 = 5.82 M` `{:(,NH_(3) ,+,H_(2)O,rarr,NH_(4)OH,hArr,NH_(4)^(+),+,OH^(-),),("Initial conc.",,,,,C "MOL" L^(-1),,,,,),("After dissociation",,,,,C-Calpha,,C alpha,,C alpha,),(,,,,,=C(1-alpha),,,,,):}` `:. [OH^(-)] = C alpha = C SQRT((K_(b))/(C)) = sqrt(K_(b)C)= sqrt((K_(w))/(K_(a))xxC)=sqrt((10^(-14))/(5.0xx10^(-10))xx5.82)=1.079xx10^(-2)M(alpha = sqrt(K_(b)//C) and K_(a)xxK_(b)=K_(w))` `:. [H^(+)]=(K_(w))/([OH^(-)]) = (10^(-14))/(1.079xx10^(-2))=0.9268xx10^(-12) M = 9.268xx10^(-13)M`