Uploaded March 2016 | Updated September 2026, 3 weeks ago
I made a hot dilute solution of magnesium sulfate and allowed it to cool. I then placed a grain of magnesium sulfate into the solution to observe the crystallisation rate over a period of 1 hour.
1) Weigh out 15 g of magnesium sulfate heptahydrate into a clean empty beaker.
2) Add 15 mL of deionised water.
3) Heat over a Bunsen flame or hot plate until all of the salt has dissolved. It is necessary to place a lid over the beaker to prevent premature and accelerated evaporation, which forms a crystal crust on the surface of the solution.
4) Flash cool the beaker in an ice-bath.
5) Place a crystal grain of magnesium sulfate heptahydrate to investigate crystallisation rate.
As you can see from the video, there was negative growth of the crystal grain. The crystal grain dissolved over time, and the experiment was halted after one hour. The solution was far too dilute, and allowed further dissolution of the salt.
I made a hot dilute solution of magnesium sulfate and allowed it to cool. I then placed a grain of magnesium sulfate into the solution to observe the crystallisation rate over a period of 1 hour.
1) Weigh out 15 g of magnesium sulfate heptahydrate into a clean empty beaker.
2) Add 15 mL of deionised water.
3) Heat over a Bunsen flame or hot plate until all of the salt has dissolved. It is necessary to place a lid over the beaker to prevent premature and accelerated evaporation, which forms a crystal crust on the surface of the solution.
4) Flash cool the beaker in an ice-bath.
5) Place a crystal grain of magnesium sulfate heptahydrate to investigate crystallisation rate.
As you can see from the video, there was negative growth of the crystal grain. The crystal grain dissolved over time, and the experiment was halted after one hour. The solution was far too dilute, and allowed further dissolution of the salt.
