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Saturday, September 26, 2015

Why do we hear a hissing sound when we open a Thumsup/Coke bottle?



The Coke is pumped with CO2 gas for carbonation process. Coke sealed under pressure condition. Partial gas gets dissolved in the liquid as bubbles and the remaining occupy the volume at the surface of the liquid and sealed cap. When the bottle is opened due to pressure difference, there is rush of gas at liquid surface to outside the bottle followed by dissolved gas rushing out from liquid making small explosions of liquid at surface leading to hissing sound and bubbles.