ScienceVerseWhat Makes Sugar Dissolve Faster?
Sign in to save this experiment.Safety first
No supervision neededNo adult supervision needed. Use cold and room-temperature water only, never hot water.
Protective equipment and “do not substitute” warnings have not been recorded for this experiment yet. They are added when its safety review is completed; until then, follow the supervision notes above.
Disposal: Pour the sugary water down the sink with running water.
Materials
- Four sugar cubes
- A small sandwich bag and a rolling pin
- Four clear cups
- Water from the fridge and water at room temperature
- A teaspoon
- A stopwatch or phone timer
Steps
- Put one sugar cube in a sandwich bag and crush it into small grains with the rolling pin.
- Pour the same amount of room-temperature water into two cups. At the same moment, add a whole cube to one and the crushed cube to the other. Do not stir. Time how long each takes to disappear.
- Pour the same amount of room-temperature water into another cup, add a whole cube and stir steadily. Time it.
- Pour the same amount of fridge-cold water into the last cup, add a whole cube and stir in the same way. Time it.
- Compare your times. Each pair of cups changes only one thing.
What you should see
- The crushed cube dissolves faster than the whole cube.
- Stirring makes the cube dissolve faster than leaving it.
- The cube in cold water takes longer to dissolve than the one in room-temperature water.
Why it works
Sugar dissolves when water molecules collide with the sugar at its surface and carry sugar molecules away into the water. Anything that makes those collisions happen more often makes dissolving faster.
Crushing the cube gives a much larger surface area for the water to reach. Stirring brings fresh water into contact with the sugar. Warmer water molecules move faster, so they hit the sugar more often and with more force.