If the acid-base reaction $\mathrm{HA}\left(\mathrm{aq}\right)+{\mathrm{B}}_{}^{-}\left(\mathrm{aq}\right)\rightleftharpoons \mathrm{HB}\left(\mathrm{aq}\right)+{\mathrm{A}}_{}^{-}\left(\mathrm{aq}\right)$ has a ${\mathrm{K}}_{\mathrm{eq}}={10}^{-4}$ which of the following statements are true?

(i) $\mathrm{HB}$ is a stronger acid than $\mathrm{HA}$

(ii) $\mathrm{HA}$ is a stronger acid than $\mathrm{HB}$

(iii) $\mathrm{HA}$ and $\mathrm{HB}$ have the same acidity

(iv) ${\mathrm{B}}^{-}$ is stronger base than ${\mathrm{A}}^{-}$

If the acid-base reaction ${\mathrm{HA}}_{\left(\mathrm{aq}\right)}+{\mathrm{B}}_{\left(\mathrm{aq}\right)}^{-}\rightleftharpoons {\mathrm{HB}}_{\left(\mathrm{aq}\right)}+{\mathrm{A}}_{\left(\mathrm{aq}\right)}^{-}$ has a ${\mathrm{K}}_{\mathrm{eq}}={10}^{-4}$;  which of the following statement are true?

$\mathrm{i}) {\mathrm{A}}^{-}$ is stringer base than ${\mathrm{B}}^{-}$

$\mathrm{ii}) {\mathrm{B}}^{-} \mathrm{and} \mathrm{HB}$ are conjugate acid-base pair

$\mathrm{iii})$The acid and base strengths cannot be compared

When hydrogen chloride $\left(\mathrm{HCl}\right)$ is dissolved in acetic acid $\left({\mathrm{CH}}_3\mathrm{COOH}\right)$  then the following equilibrium is established like

${\mathrm{CH}}_3\mathrm{COOH} +\mathrm{HCl} \rightleftharpoons {\mathrm{CH}}_3{\mathrm{COOH}}_2^{+} + {\mathrm{Cl}}^{-}$ 

Which of the following set is correct respective to conjugate acid-base pair ?

$\mathrm{BOH}$ is a weak base. The molar concentration of $\mathrm{BOH}$ that provides an $\left[{\mathrm{OH}}^{-}\right]$ of $1.5\times {10}^{-3} \mathrm{M}$ is

$\left[{\mathrm{K}}_{\mathrm{b} }\left[\mathrm{BOH}\right]=1.5\times {10}^{-5} \mathrm{M}\right]$