\(\mathrm{HZ}\) is a weak acid. An aqueous solution of \(\mathrm{HZ}\) is prepared
by dissolving \(0.020\) mol of \(\mathrm{HZ}\) in sufficient water to yield \(1.0
\mathrm{~L}\) of solution. The \(\mathrm{pH}\) of the solution was \(4.93\) at
\(25.0{ }^{\circ} \mathrm{C}\). What is the \(K_{\mathrm{a}}\) of \(\mathrm{HZ}\) ?
