A weak base BOH is tirated against 0.1 M of HCl solution. The following table indicates the volumes of HCl added and pH of solution. From this data the pK_b of base may be.

A weak base BOH is tirated against 0.1 M of HCl solution. The followin

1.	A weak base BOH is tirated against 0.1 M of HCl solution. The following table indicates the volumes of HCl added and pH of solution. From this data the pK_b of base may be.
Answer» `4.74` ` 4.3` ` 4.9 ` ` 4.5` Solution :`POH =pK_b +log ""( S)/(B) ` ` 14- 10.04 = pK_b +log ""( 0.1 xx 5 )/(40 B -0.1 xx 5) ` ` rArr 3.96 =pK_b +log ""( 0.5 )/(40 B -0.5 )......(1) ` ` 14- 9, 14 =pK_b +log"" ( 0.1 xx 20)/( 40 B -0.1 xx 20 ) ` `rArr 4.86 = pK_b +log ""( 2)/(40B - 2) ....(2) ` ` 0.9 = log"" ( 2)/( 40 B-2) xx ( 40 B -0.5 )/( 0.5 ) ` ` 8 = 4xx ( 40 B-0.5)/( 40 B -2) rArr 80 B -4 =40 B -0.5` ` 40 B =3.5 rArr B =(3.5)/(40) ` substituting in (1) ` 4.86 =pKb+ log"" (2)/(3.5-2 )rArr pK_b =4.74`