Does sugar dissolve better in cold or hot water?

Sugar dissolves much better in hot water -- the hotter the better. Try it: add the same amount of sugar to two cups, each with the same amount of water, except in one glass add ice cubes to the water, and in the other use water heated on the stove. See which dissolves the sugar faster!

Most solids (although not all) are more soluble when the solution is hotter (although gases are generally less soluble the hotter the solution).