To separate sugar from its mixture with sand, a proportionally large amount of water is added to the mixture and shaken vigorously to allow the sugar to dissolve. The solid-liquid mixture is filtered using a porous material to retain the sand on the filter and to allow the liquid portion to pass through. The liquid contains the sugar originally present in the solid mixture.
In a laboratory setting, prepare a mixture of known amounts of sand and sugar in a test tube or flask. Add water to the mixture's container, then shake the container to allow the sugar to dissolve properly in the water. Meanwhile, set up a filtration system consisting of a funnel, a fan-folded filter paper and a filtrate flask. Dispense the solid-liquid mixture from the container to the filtration setup. Through this process, sand is retained on the filter paper, while the sugar solution passes through the paper as the filtrate. If both materials need to be recovered in pure form, the sand and the sugar solution may be dried up by evaporating the water.
The physical separation of sand and sugar is made possible by their differences in solubility. Sand is insoluble in water, while sugar is readily dissolved as soon as it comes in contact with water.