After the microwave reaction, there was a warning to open the reactor carefully
ID: 519755 • Letter: A
Question
After the microwave reaction, there was a warning to open the reactor carefully because it might be pressurized. One cause of this pressure is due to the reactor being at a higher temperature than when it was sealed, one of the standard "gas laws" from gen-chem. What is another likely cause of pressure? For example, is there another gaseous chemical present, and if so, what is it? Or if there is no other gaseous chemical, explain in one sentence one other specific possible reason for the increase in pressure.
(potassium carbonate and water were added)
Explanation / Answer
Microwave reaction is the reaction of microwave radiation to chemicals. Microwaves act as high frequency electric fields and will generally heat any material containing mobile electric charges, such as polar molecules in a solvent or conducting ions in a solid. Polar solvents are heated as their component molecules are forced to rotate with the field and lose energy in collisions.
When microwave reaction takes place under high radiation, high temperature is generated. This generated heat causes to increase the temperature of surrounding gases in the microwave. As, temperature increase, their kinetc energy also increases, causing in increase of pressure. There are always gases like CO2 , CO, inside the microwave. so, due to high temperature, their kinetic energy increases and collison of molecules with the wall and molecules with molecules both increases. thus ultimately leading in pressure.
Potassium carbonate reacts with water, it dissolves giving 2K+ and one CO3 2- ion. There are also H+ and OH- ions from the water.
Since carbonic acid is a very weak acid, there will also be equilibria to that and HCO3- from the ions.
weak acid H2CO3 Conjugate base HCO3-
H+(aq) + HCO3-(aq) <--> H2CO3(aq). It may form CO2 gas in some amount which will cause increase in pressure.