Base eg: $NH_3$, $CH_3NH_2$ , $CN^-$, $ClO^-$ .. Acid eg: $HCl$, $HNO_3$, ...
To have a reliable result we will choose (approximate formulas used, see → here ): A molarity of the titrated base of between 0.05 mol/L and 0.2 mol/L - As molarity of the titrating acid 0.05 mol/L or 0.1 mol/L or 0.2 mol/L - As volume of the base 10 mL or 20 mL or 25 mL The $pK_a$ of the acid/base couple between 5 and 11