In: Chemistry
Find αH2A for a diprotic acid (H2A) at pH 1.00 (Ka1 = 1.20 × 10-2 & Ka2 = 5.37 × 10-7)
We have equation, H2A = [H+] 2 / [H+] 2 + K 1 [H+] + K 1 K 2
We have given K 1 =1.20 10 -02 , K 2 =5.37 10 -07
We have, pH = - log [H+] .
Therefore, [H+] = 10 - pH = 10 - 1.00 = 0.10 M
Putting above values in equation, we get
H2A = (0.10 ) 2 / (0.10) 2 + (1.20 10 -02 0.10 ) + ( 1.20 10 -02 )( 5.37 10 -07 )
H2A = 0.01 / 0.01 + 1.20 10 -03 + 6.444 10 -09
H2A =0.01 / 0.0112
H2A = 0.893