sodium bicarbonate caking?

[Oumati Asami]

Would sodium bicarbonate absorb moisture from air and become a cake?
Many solids do that. Not sure if sodium bicarbonate would also.

[Norm Why]

Would sodium bicarbonate absorb moisture from air and become a cake? Many
solids do that. Not sure if sodium bicarbonate would also.

Yes, I think it would with time and humidity. Sodium bicarbonate in its box
is often put into refrigerators to absorb smells. To be regenerated requires
heat. But to do so would release CO2 and convert sodium bicarbonate to
sodium carbonate,

2NaHCO3 -> Na2CO3 + CO2 + H2O

So most people just throw away the box when it becomes stale.

[Libor Striz]

Would sodium bicarbonate absorb moisture from air and become a cake? Many solids do that. Not sure if sodium bicarbonate would also.

It is more complicated, as it slowly decomposes:

2 NaHCO3 -> Na2CO3 + H2O + CO2.

[Frank]

Post by Libor Striz

Would sodium bicarbonate absorb moisture from air and become a cake? Many solids do that. Not sure if sodium bicarbonate would also.

2 NaHCO3 -> Na2CO3 + H2O + CO2.

Mechanisms have been elucidated:

https://www.jstage.jst.go.jp/article/shigentosozai/118/7/118_7_511/_article/-char/en

I had to look up this one: Wegscheider's Salt (Na 2 CO 3 3NaHCO 3 )