You will need
  • Battery electrolyte, glass jar, saucepan, engine oil, electric.
In industry it is obtained by dissolving sulfur trioxide (sulphur trioxide) in water. And for dioxide, sulfur dioxide formed, for example, after roasting sulphide ore or obtained by direct method (by burning sulphur in oxygen), oxidize to sulfuric anhydride at a temperature of 500 degrees centigrade for the catalysts of platinum, vanadium oxide, and the like. But, what would you get concentrated sulfuric acid in the handicraft way, not necessarily to resort to the above trick. In the automotive store to buy a battery electrolyte, take an ordinary glass jar and pour it in there, then take the pan, pour in the motor oil (it will come down and practicing) and put there the jar. Then everything is placed on the stove.
Thus, there is evaporation of water from the electrolyte. Trick oil bath is that the temperature of boiling oil is somewhat larger than the boiling point of water and thus the water quietly boils and the butter is not boiling and the glass jar is intact, as is heated uniformly over the entire area. Even hot concentrated sulfuric acid does not react with glass, so the amount of impurities in it is minimal. The process can be carried out in the temperature range from 100 to 300 degrees, but it is better not exceed the boiling point of the oil. Continue the process until until water boils away. In principle, concentration of sulfuric acid can be produced in a solid metal container, but after that the acid is heavily contaminated with impurities and will have a darker color, and besides, it is likely that the capacity in the process will leak.