Every day I mix two parts of ascorbic acid powder with 1 part of sodium bicarbonate powder and place the resulting powder into an airtight container. I have noticed that if the resulting powder is mixed with water within 30-60 minutes, it fizzles indicating the release of carbon dioxide as a byproduct of the acid-base reaction. However, if I leave it untouched (within a dry and airtight container) for 6 to 8 hours, it hardens. If I crush it (so it turns into powder again) and mix it with water, it no longer fizzles.
My questions are:
Why does it harden and no longer fizzles if mixed with water after a few hours? Does the acid-base reaction take place even without adding any liquids to the mixed powder?
Most importantly, does the reaction that causes the hardening and absence of fizzling cause any kind of degradation (e.g., oxidation) to the ascorbic acid? In other words, can I mix ascorbic acid with sodium bicarbonate (both in powder form), store the resulting powder in an airtight container and consume over a few months? Would that diminish the efficacy of the Vitamin C in any way?
Thank you in advance.
I have bought sodium bicarbonate from a different manufacturer and now after mixing it with ascorbic acid, nothing happens until water is added. It can sit for 24+ hours, without hardening and it will still fizz when mixed with water. I suspect the sodium bicarbonate from the previous manufacturer was slightly moist and this one is completely dry.