posted by jurgen .
why does there come out a foam like silver bubbles wen you mix dilute sulpheric acid and magnesium metal oxide
Dilute sulfuric acid means water is there also.
I suspect you have a mixture of magnesium oxide, magnesium, water, and sulphuric acid.
What happens depends on how much of each.
Magnesium and acid yields hydrogen bubbles
Magnesium and water yields hydrogen bubbles and magnesium hydroxide.
magnesium hydroxide and acid yields water and magnesium sulfate.
I suspect you have a mixture of all this.