Potassium nitrate crystals Watch

William123456
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How do you obtain crystals of potassium nitrate from potassium nitrate solution
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Nour M.
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This all is built on the basis of crystallisation (forming crystals due to the difference in solubility). Now, you might recall that solubility increases with temperature. Potassium nitrate has a remarkably large difference between its solubility in hot and cold water - 2460 grams per liter at 100°C, and only 133 g/L at 0°C. The whole process goes like this:

- First dissolve potassium nitrate in hot water, as much as possible until no more dissolves (saturation of solution)
- Let the water cool down (potassium nitrate crystals will start to form as the solution becomes super-saturated and is no longer able to keep the potassium nitrate dissolved due to a lower solubility at lower temperatures)

Alternative method:
- Dissolve potassium nitrate in room temperature water until saturation (no more dissolves)
- Heat up the solution until some of the water evaporates (as water evaporates the overall concentration of the solution increases and the solubility decreases as there is less solvent)
- As the water cools down, potassium nitrate crystals will start to form (due to the solution not be able to dissolve as much potassium nitrate because there is less solvent/water. Also, as the temperature decreases, solubility decreases, causing more crystals to form)

Hope I was able to help
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