The technique used to separate sodium chloride (salt) and sugar is recrystallization.
How Recrystallization Works
Recrystallization leverages the difference in solubility of salt and sugar in water. Here's how it works:
- Dissolving: Both salt and sugar dissolve in water, but sugar is more soluble than salt.
- Evaporation: When the water evaporates, the sugar crystals start to form first because it is less soluble.
- Separation: The sugar crystals can be separated from the remaining solution, leaving the salt behind.
Practical Insights
- Temperature: The process works best at high temperatures because both salt and sugar are more soluble in hot water.
- Evaporation Rate: A slow evaporation rate allows for the formation of larger, purer sugar crystals.
Example
Imagine a mixture of salt and sugar in a beaker. You add hot water and stir until both substances dissolve. As the water slowly evaporates, the sugar crystals will form first, leaving the salt dissolved in the remaining water. You can then filter the solution to separate the sugar crystals from the salt solution.
