Year 5 have started the New Year by setting up a science experiment. Our aim was to see if we could get salt back from water once it had dissolved.
The pupils worked together to set up a fair experiment. We mixed some salt into a jug of tap water. Pairs of pupils observed to make sure that the salt had dissolved in the solution.
Two identical petri dishes were then used. We transferred some of the solution from the jug to the petri dishes using a pipette.
One of the petri dishes was sealed with a lid. The other was left open. These were then left out in the same location for a 24 hour period.
We returned to our experiment a day later to analyse the results. The pupils found that the petri dish with a lid hadn’t altered. The water solution was still contained inside.
The petri dish with no lid was now displaying tiny rocks of salt. All the water had evaporated from the solution leaving only the salt solids.
Year 5 concluded that it is possible to get salt back from water, but only under certain conditions. You need to make sure that the salt solution is able to go through the process of evaporation.