But does the concentration of sugar in the water affect the reaction? Like, would a more dilute formula slow the reaction, producing less CO2 but prolonging it?
Don't take me to the bank on this, but...I think having more water would slow the process making it last longer. Not because of anything to do with the sugar or the yeast, but because what ultimately happens is that this process starts fermenting and creating alcohol. It is this rise in the amount of alcohol that kills off the yeast and stops your reaction. Therefore, I think more water might, maybe, slow this "burn out" process as the produced alcohol would take longer to rise to high levels when diluted with more water.
I have nothing to back this up. It's a theory.