of sulfuric acid produced in various ways, the most common "pin."The raw materials are a variety of sulfur-containing ores, mainly pyrite (iron sulfide, FeS2).In the first step of the process, as a result of firing, it forms a sulfur oxide SO2.Subsequently, the gas purified of dust and impurities by oxidation of the sulfur dioxide is converted to SO3, of which already forms sulfuric acid H2SO4.
For example, you have been given a few samples of liquids, which include sulfuric acid.First of all, you need to make sure that it really is acid.Of course, in any case not probovuyte samples to taste.Alternately in each tube,
add a piece of zinc.Those tubes, which immediately begin vigorous reaction with evolution of gas, probably contain acid.
Why do you use that zinc instead of alkali or alkaline earth metal?Because they are just pushed to hydrogen and pure water, and a solution of any salt.Instead of clarity, you would only get confused.Zinc allows you to pinpoint acid.
separate them from the rest of the samples and look where it is sulfuric acid.To do this, use a quality characteristic reaction to sulfate ion.Add to each tube a little solution of barium chloride (BaCl2).Reacts with sulfuric acid, it immediately forms a white precipitate of barium sulphate tight (BaSO4), under the scheme:
BaCl2 + H2SO4 = BaSO4 + 2HClVypadenie this precipitate indicates the content of sulfuric acid in the sample.