In the equilibrium solution of hydrofluoric acid, $[\text{H}^+]$ is constant and equal to $[\text{HF}]$.
In the ionic dissociation of hydrogen chloride gas in water, ammonium ion and chloride ion are formed at equal concentrations.
At equal molar concentrations, the acidity of formic acid solution is less than that of acetic acid solution.
If $[\text{H}^+]$ in solution HA is less than $[\text{X}^-]$ in solution HX, then the pH of solution HX is greater than the pH of solution HA.
\textbf{95.} Which case is correct?
\begin{enumerate}
\item In the equilibrium solution of hydrofluoric acid, $[\text{H}^+]$ is constant and equal to $[\text{HF}]$.
\item In the ionic dissociation of hydrogen chloride gas in water, ammonium ion and chloride ion are formed at equal concentrations.
\item At equal molar concentrations, the acidity of formic acid solution is less than that of acetic acid solution.
\item If $[\text{H}^+]$ in solution HA is less than $[\text{X}^-]$ in solution HX, then the pH of solution HX is greater than the pH of solution HA.
\end{enumerate}