2.5 mL of 25M weak monoacidic base (Kb=1×10−12) at 25oC is titrated with 215M HCl in water at 25oC. The concentration of H+ at equivalence point is (Kw=1×10−14 at 25oC)
2.7×10−2M
mmol of base =2.5×25=1
mmol of acid required to reach the end point = 1
Volume of acid required to reach the end point = 152mL
Total volume at the end point = 152 + 2.5 = 10 mL
Molarity of salt at the end point = 110=0.10
B+C(1−α)+H2O⇌BOHCα+H+Cα
Kh=KwKb=10−2
Kh=10−2=Cα1−α=0.1α1−α
⇒ 10α2+α−1=0
⇒ α=−1+√1+4020=0.27
⇒ [H+]=Cα=0.1×0.27=0.027M