Sugar Solubility

Most recent answer: 10/22/2007

Q:
Does hot water dissolve more sugar than cold water? Why?
- sheley (age 12)
A:
I’m pretty sure, just from cooking, that hot water does dissolve more sugar than cold water. Assuming that’s right, there’s a pretty simple reason. It takes energy to pull a sugar molecule off a sugar crystal and insert it into the liquid water. When the water is hotter, there’s more random thermal energy around, making it easier for that process to happen.
Imagine you had a bowl of marbles. They have high energy states (up the bowl) and low energy states (down in the bowl). The more you shake up the bowl (like heating the water) the more time the marbles spend up in the high energy states. So it looks like the dissolved sugar has higher energy than the separate sugar and water.

Mike W.

(published on 10/22/2007)