H_3Ais a weak triprotic acid(K_(a_1) =10^(-5),K_(a_2)=10^(-13)) . What is the value of pX of 0.1 M H_3 A(aq.)solution ? WherepX=- log X and X = ([A^(3-)])/([HA^(2-)])

H_3Ais a weak triprotic acid(K_(a_1) =10^(-5),K_(a_2)=10^(-13)) . What

1.	H_3Ais a weak triprotic acid(K_(a_1) =10^(-5),K_(a_2)=10^(-13)) . What is the value of pX of 0.1 M H_3 A(aq.)solution ? WherepX=- log X and X = ([A^(3-)])/([HA^(2-)])
Answer» `7` `8` `9` ` 10` Solution : ` H^(+)` ionsfrom ` I^(st) `step is onlyconsidered ` [H^(+) ] =sqrt(Ka_1 xx C) =sqrt( 10 ^(-6)) =10 ^(-3)M` ` X =([A^(3-)])/( [HA^(_2) ]) =(Ka_3)/([H^(+) ] )rArr X =10 ^(10)rArr PX =10 `