Change one condition
Keep two conditions matched to the cool, unstirred, coarse-grain reference to investigate the third.
Dissolving Detective
Compare how water temperature, stirring and sugar grain size change the rate of dissolving.
Grades 3–5 · Chemistry
Your goal
Compare warm water, no stirring and coarse sugar grains. Advance 2 observations.
Reduced motion is on. The controls still update the scene.
Observation 0. Both cups have dissolved the same amount so far. The cups have matching conditions. Advance observations to compare the rates.
The reference uses cool water, no stirring and coarse grains. Changing a test condition restarts both cups so their observation times stay equal.
This is a qualitative illustration, not a prediction of seconds. Each enlarged dot or grain cluster represents one equal sugar unit. Both cups hold a small sugar quantity well below saturation, so all of it can eventually dissolve. Stirring and grain size change the rate, not how much can dissolve at equilibrium. Solubility is a different question and can also depend on temperature.
Related resources
Related simulations
Learn with Dissolving Detective
Dissolving Detective helps elementary students investigate why sugar dissolves at different rates. Compare two cups holding the same small sugar amount and water volume, then change the test cup’s temperature, stirring or grain size. Advance equal observation intervals and follow the sugar as it moves from visible grains into the water. Changing one condition at a time makes a fair comparison. The activity separates dissolving rate from solubility and shows that dissolved sugar remains present, even after the visible grains are gone.
What to look for
Observe equal intervals
Advance observations for both cups together. Changing conditions restarts both samples.
Sugar stays in the water
Dissolved sugar has not disappeared. Both samples contain the same total amount throughout.
For teachers and curious learners
Use equal sugar samples to compare dissolving rates while distinguishing rate from solubility. Ask students to predict what will happen, change one setting, and explain what they observe. Learn gives a starting point. Practice and Challenge offer new goals with the same scene.
Qualitative observations illustrate rate, not measured seconds. Equal small sugar quantities stay well below saturation. Stirring and grain size change rate rather than equilibrium solubility.