In this home scientist video the instructor Robert Bruce talks about cheap sulfuric acid. He says that sulfuric acid is very important in any lab both as a reagent and a precursor for preparing other chemicals. He points to the battery acid saying that it is a good source of sulfuric acid which is 35% concentrated. Now he shows various methods to obtained sulfuric acid and shows how to test one of the thus obtained sulfuric acid for its concentration. In this video the author talks about sulfuric acid and shows how to find the concentration of it.