Скачать или смотреть Frozen Acetic Acid glacial mixed with bicarbonate

Glacial acetic acid (99.7% pure) freezes at 16.6 degrees Celsius. I put some acetic acid in the fridge and freezer. The fridge did not freeze the acid (within an hour) so I moved it to the freezer. The frozen acid included some vapors that had frozen in the top air space in the beaker, but these quickly melted back in the classroom.

Adding sodium carbonate (solid) or sodium bicarbonate (aqueous) caused very little reaction. Even as the mixture warmed little bubbling happened. This is surprising because as water is produced or added, the acetic acid should melt. The melting point of vinegar is much lower than pure glacial acetic acid.

Potentially the low temperature plays a role in the thermodynamics where the low temperature minimizes the increase in entropy of the system during the reaction preventing the reaction from being spontaneous at the low temperature.