pH of 0.01 M solution of HA is 4. Find the value of pKa of HA at ${25}^{\circ }C$

Q. A given weak acid (0.01M ) has $p{K}_a=6.$ the pH of the solution is :

Q. A given weak acid (0.01 M) has $p{K}_a=6$ .The pH of the solution is

Q. The $pH$ of a $0.01M$ $HCN$ solution for which ${pK}_a$ is $4$ is:

Q. At ${25}^{\circ }C$ disociation constant of acid $HA$ and base $BOH$ in aqueous solution are same. The $pH$ of $0.01M$ solution of $HA$ is $5$. The $pOH$ of ${10}^{-4}$ M solution of $BOH$ at the same temperature is:

Q. The molar conductivity of aqueous solution of a weak acid, $HA$ is $200{\text{S cm}}^2{\text{mol}}^{-1}$ and its $\text{pH}$ is $4$. What is the value of ${\text{pK}}_a$ of $HA$ at ${25}^{\circ }\text{C}$?
(Given:${\lambda }_m^0\left(NaA\right)=100{\text{S cm}}^2{\text{mol}}^{-1},{\lambda }_m^0\left(HCl\right)=425{\text{S cm}}^2{\text{mol}}^{-1},{\lambda }_m^0\left(NaCl\right)=125{\text{S cm}}^2{\text{mol}}^{-1}$)