What will happen when dry ice is dropped into gasoline?
need to settle a bet, will this cause an explosion or no?
gRod:
There is no reason that simply dropping dry ice into an open container of gasoline should cause an explosion on it own. There is no source of ignition.
With this said there is a greater potential for an explosion, but it is not the direct result of the dry ice. The dry ice will sublime off and form a layer of CO2 gas above the gasoline.
Since this happens quite energetically there will be a lot of additional gasoline vapor put into the atmosphere. If the gasoline vapor in the air reaches and ignition source then there will be an explosion.
Remember that the flashpoint of gasoline [1] is -40F, so DO NOT try this experiment at home.
Niel
Theory 1: Dry ice is frozen CO2. When it hits the ‘warmer’ gasoline, it will thaw producing gaseous CO2. This will blanket the gasoline and reduce likelihood of combustion to occur.
Theory 2: It’s fumes from gasoline (gaseous gasoline) that is flamable. Two things come to mind that cause liquid gasoline to convert to gaseous gasoline: temperature (flash point is -40F) & reduced pressure. So introducing a cooling agent (ie. dry ice) will once again reduce the likelihood of combustion.