Evaporation experiments for kids: Salt with a difference – evaporation on wool
Two jars of salt solution, a piece of wool and about 1-2 weeks of patience is needed for this experiment.
In this experiment you need:
- 2 glasses
- a wool thread
- (and a little time)
In the two glasses we provide water and dissolve as much salt, that a small residue remains undissolved salt lying on the ground. Now we have a saturated solution. Now we put the two glasses side by side (on a radiator would be ideal).
The wool yarn is wetted completely. Now the thread is stretched as a line between the two
glasses, each with one end of the thread must be immersed in a glass.
The experiment is now a bit boring, because nothing happened at first time. After hours (depending on ambient temperature and humidity or even days) salt is formed on the surface of the wool yarn.
The reason for this is that evaporating water contained in the solution, but the salt can not evaporate and thus depend on wool remains. The result is a lump of salt, which is gradually getting heavier. Then it may happen that the wool thread through much depends.
Funny side effect: If the lump of salt is too big or heavy, then he falls off the thread and a new
lump begins to form. It also depends on how much slack in the thread. Is his lowest point below the water level in the glasses, then it may happen that it all starts to drip.
Interesting Facts of Evaporation Experiments For Kids:
Why the drops disappear after a while?
The refrigerator manufacturers know the effect of condensationand freezing of water droplets for a long time. It is an unwantedside effect, since the cooling function, the worse the moredroplets are frozen on the back wall.
A remedy was created with the automatic defrost feature of modern refrigerators. This feature makes the rear wall is heatedintentionally short. The dew drops and begin to walk in littlerivulets down the wall. You can not just run the resulting melt water in the refrigerator, but it is collected in a gutter in anevaporation tank and half out of the refrigerator is collected,where it can evaporate.