norganic acids and anhydrides thereof should first be diluted or hydrolyzed by stirring carefully into ice water and then neutralized (protective gloves, fume cupboard!) with sodium hydroxide solution (Cat. No. 105587). Before filling into container D, check the pH with pH universal indicator strips (Cat. No. 109535). Fuming sulfuric acid should be carefully stirred dropwise into 40 % sulfuric acid (Cat. No. 109286). Ensure that plenty of ice is available for cooling! When sufficiently cool, treat the highly concentrated sulfuric acid as described above. Analogous to this procedure, other anhydrides can be converted into their corresponding acids. Acid gases (e.g. hydrogen halide, chlorine, phosgene, sulfur dioxide) can be introduced into dilute sodium hydroxide solution and after neutralization disposed of in container D.