JEE Main Chemistry question
2.5 mL of 2/5 M weak mono acidic base (Kb=1×10⁻¹² at 25°C) is titrated with 2/15 M HCl in water at 25°C. The concentration of H⁺ at equivalent point is (Kw=1×10⁻¹⁴ at 25°C):
Answer: (C)
Solution
mmol base=1.0; volume HCl=1.0/(2/15)=7.5 mL; total 10 mL; salt conc.=0.1 M. Ka(conj. acid)=Kw/Kb=10⁻²; [H⁺]=√(10⁻²×0.1)=3.2×10⁻² M.