Dissolving Sugar at Different Heats
Learn about solutions as you add more and more sugar cubes to different temperature
water. This easy experiment shows that you can only dissolve a certain amount and that this
changes as the water gets hotter.
What you’ll need:
Cold water in a clear glass
Hot water in a clear glass (be careful with the hot water)
Spoon for stirring
1. Make sure the glasses have an equal amount of water.
2. Put a sugar cube into the cold water and stir with the spoon until the sugar
disappears. Repeat this process (remembering to count the amount of sugar cubes
you put into the water) until the sugar stops dissolving, you are at this point when
sugar starts to gather on the bottom of the glass rather than dissolving.
3. Write down how many sugar cubes you could dissolve in the cold water.
4. Repeat the same process for the hot water, compare the number of sugar cubes
dissolved in each liquid, which dissolved more?
The cold water isn’t able to dissolve as much sugar as the hot water, but why? Another
name for the liquids inside the cups is a ‘solution’, when this solution can no longer dissolve
sugar it becomes a ‘saturated solution’, this means that sugar starts forming on the bottom of the cup.
The reason the hot water dissolves more is because it has faster moving molecules which are spread further apart than the molecules in the cold water.
Wbiggergaps between the molecules in the hot water, more sugar molecules can fit in between.