NH_4 OH hArr NH_(4)^(+) + OH^(-) ,K_b = 2 xx 10^(-5) .If one litre of a solution contains 0.1 mole each of ammonia and ammonium sulphate, calculate the pH of buffer solution

NH_4 OH hArr NH_(4)^(+) + OH^(-) ,K_b = 2 xx 10^(-5) .If one litre of

1.	NH_4 OH hArr NH_(4)^(+) + OH^(-) ,K_b = 2 xx 10^(-5) .If one litre of a solution contains 0.1 mole each of ammonia and ammonium sulphate, calculate the pH of buffer solution
Answer» Solution :`k_b` of `NH_4 OH= 2 XX 10^(-5)` HENCE `pK_a` of `NH_4 OH=- logk_b = 5- LOG 2` ` [NH_3] =0.1mol, [NH_(4)^(+)]=2[ (NH_4)_2 SO_4]=0.2mol` ` pOH= pK_b + log""([NH_(4)^(+) ])/([NH_3]) = 5- log 2 + log (0.2 )/( 0.1 ) = 5.0` ` pH =-pOH=14-5=9`