Recrystallization is the most important method of purifying nonvolatile organic solids. Recrystallization involves dissolving the material to be purified (the solute) in an appropriate hot solvent. As the solvent cools, the solution becomes saturated with the solute and the solute crystallizes out (reforms a solid).
- 30 gm Oxalic acid was weighed.
- 40 ml of Distilled was was taken in a glass beaker.
- The beaker was placed on magnetic stirrer and hot plate was switched on.
- Slowly oxalic acid was added to the distilled water with consant stirring and heating. This was done because heating increases the solubility. Oxalic acid was added till the saturaton point where no oxalic acid will be dissolved on addition.
- When we reached to saturation point, we stopped heating, allowed the solution to cool down. From 30 gm of oxalic acid, 21.13gm was abled to dissloved in 40ml of distilled water.
- Once the solution was cooled down, it was filltered with the help of funnel and filter paper.
- The recrystallized oxalic acid got collected onto the filter paper. Later this oxalic acid was scraped and taken in petri plate.
- The intial weight of the scraped oxalic acid was taken which was 25.035 gm.
- Then it was place in hot air oven and dried at 100 degree Celcius till the weight becomes constant. On complete drying, the oxalic acid was weighed which was 17.475 gms.
- 21.13 gm of oxalic acid got dissolved completely in 40 ml of distilled water and the solution reached to its saturation point where oxalic acid was not getting dissolved on further addition.
- On drying the filtered Oxalic acid, 17.475 gm purified oxalic acid was obtained.