Reaction of acedified potassium dichromate with the alkene

The reaction of potassium dichromate with an alkene is similar as with potassium permanganate. it will oxidize the alkene but it will completely oxidize it.  In the first step of the reaction, the alkene becomes a diol, then it oxidizes the diol to produce a ketone or carboxylic acid.  I have pasted some examples below 

By far the most abundant volcanic gas is water vapor, which is harmless. However, significant amounts of carbon dioxide, sulfur dioxide, hydrogen sulfide and hydrogen halides can also be emitted from volcanoes.