Sulfuric acid in steel tank?

Question

why can concentrated sulfuric acid be stored in mild steel tanks, but not dilute sulfuric acid?

(in simple terms please!)

Answer 1

So simple , you see ! 'cos if u hav read 'bout acids and bases in your coursebooks you would probably remember that concentrated acids are less reactive than dilute ones as they would corrode the steel  !!

Answer 2

I think it can't ionise in concentrated solution due to a lack of water i.e. it can't form h2so4+h20-> h3o+  = hso4- and therefore won't react with the steel surface to form H2 gas ( explosive) and iron sulfate. In dilute solution its mixed with water so it would produce H2 gas and ferrous sulphate...erode the steel