|MadSci Network: Chemistry|
I hope that my way to approach this problem is right. There are two components in the height of the bubbles - first, the amount of CO2 formed by the reaction
2 C2H5COOH + Na2CO3 -> CO2 + 2 C2H5COONa + H2O
and, secondly, the efficiency with which the bubbles are formed.
There is probably no doubt about the fact that this reaction proceeds faster if the temperature is higher (A good rule says, that a chemical reaction is twice as fast if the temperature is 10 degrees higher - means that if you have a difference of, say, 50 degrees, it is 32 times as fast!). Then the only possible explanation is the the second point - maybe the bubbles burst much more readily at higher temperatures? Maybe not all of the gas is trapped in the bubbles, because at higher temperatures there's such an amount of gas formed that most of the bubbles burst?
I think that's the point - the efficency with which the gas is trapped may be lower and/or the bubbles burst much faster, resulting in what you observed.
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