In our chemistry lab we've been observing this eraser inside a bottle hanging from a pencil. (decription of the model) There is water inside the bottle and the eraser is tied with a rope hangin from a pencil. The more we observed everyday .. the more salts we see at the bottom of the bottle and also more on the rope and pencil. however there is no salt on the eraser that's been in water for almost 11 weeks now. Why is there more salt at the bottom of the bottle, rope, and pencil but none on the eraser?
2006-11-10 06:43:27 · 2 answers · asked by mizz ADOHRable 1 in Science & Mathematics ➔ Chemistry
Being the eraser is rubber (or something similar), it tends to not interact with polar materials (water, ionic materials like salt, and the like). Because of this, salt crystals rarely get a place to start growing on the eraser. The string is likely made of cotten or cotten containing, which has polar elements where the salt could adhere and start growing.
The bottom of the container doesn't need to have anything adhere to it, gravity keeps the salt which has crystalized and not sticking to something, at the bottom.
2006-11-10 07:17:22 · answer #1 · answered by Radagast97 6 · 0⤊ 0⤋
I'd say it's because the eraser is made up of non-polar molecules, so the crystals, which are ionic solids, won't adhere to it.
2006-11-10 14:57:26 · answer #2 · answered by pack_rat2 3 · 0⤊ 0⤋