Nitric acid
Into a 250ml flask with stirbar, set up for distillation, were carefully1 introduced 122g 93% H2SO4 (1.16mol), 100g NaNO3 (1.18mol) and 74ml H2O. The flask was heated on oil bath with stirring and a yellow liquid was distilled off (128C)2. When the distillation speed slowed considerably and the temperature in the stillhead dropped below 100C a first fraction was taken (96ml, 126.85g), 37ml H2O where added and a second fraction was distilled off (36ml, 37.83g). Both fractions were titrated against NaOH to give 10.8mol/l resp. 1.3mol/l3. The two fractions were combined and diluted to 382ml to give 382ml of an 18% HNO3 solution. (Yield: 92% from NaNO3)
Notes:
1: And I mean carefully, this gets _very_ hot.
2: At first some nitrous oxides (orange gas) are produced. But the amounts are so small that there is no danger whatsoever.
3: 4g NaOH were dissolved in 1l H2O to give a 0.1N solution, 1ml of reaction mixture was diluted to 100ml and 10ml of this solution were titrated against the NaOH solution. Usually the NaOH itself would have to be titrated against an acid of known concentration, but the results fit very well with the measured densities.