question_answer

Molar conductivity of aqueous solution of HA is \[200\text{ }S\text{ }c{{m}^{2}}\text{ }mo{{l}^{-1}}\], pH of this solution is 4. Calculate the value of \[p{{K}_{a}}(HA)\] at \[25{}^\circ C\]. \[Given:\,\wedge _{M}^{\infty }(NaA)\,100\,Sc{{m}^{2}}\,mo{{l}^{-1}};\,\wedge _{M}^{\infty }(HCl)\] \[=425\,\,Sc{{m}^{2}}\,mo{{l}^{-1}};\] \[\wedge _{M}^{\infty }\,(NaCl)=125\,Sc{{m}^{2}}\,mo{{l}^{-1}}\]

Answer:

4