Sulfur  water+UI        ................  burning sulfur:...................dissolving the combustion gases
.............................

wat02 Acid Rain due to the combustion of sulfur or its compounds

* Left photo: Transfer some sulfur powder (S)  on an aluminium container of a tea light.
* Assemble an apparatus to collect the combustion gases of S.using the following items:
  Glas pipette tube from nose or eye drops, a piece of transfusion tubing, 10-ml injection bottle with stopper pierced by a thin and strong drinking straw.
* Remove the glass pipette from the rubber bulb. Soften the end of the plastic tubing and push it over the small end of the pipette glass.
* Let the end of the drinking straw end in water at the bottom of the bottle. * Add drops of universal indicator.
* Connect the upper end of the straw with the plastic tubing and the glass pipette.
* Pierce the stopper (aside the straw) by the needle of a 20-ml syringe.
* Middle photo: Ignite the sulfur. Bring the mouth of the pipette above the blue flame. Suck the combustion gases through the indicator solution.Observations Right photo:  The colour universal indicator (UI) changes from yellow to red.
Explanation:  Sulfur dioxide (SO₂) is formed during the combustion of sulfur or of fuels containing sulfur.
This gas reacts with water forming an acid that was indicated by UI.(It is sulfurous acid. Sulfuric acid By reaction can be formed after the reaction of SO₂ whith  more oxygen.)