science for tinies: immiscible liquids

[psocoptera]

Project: Will It Mix?
Materials: water, dyed pink; peanut oil, not so much dyed green as speckled with innumerable tiny green droplets because, haha, food coloring is also immiscible with oil; mixing vessel
Explanatory details: pour together, observe
How did it go: Laboratory erupted into chaos when the PI poured the pink water not *into* the mixing vessel but mostly *next to* the mixing vessel; assistant promptly sprang into action with towels, but pursuit of science was delayed. Experiment eventually resumed with assistant doing the work and PI observing and taking credit, as is the natural order of things anyways. Very nice layering for a minute or two then food dye start coming down from the oil into the pink water, turning it murky and confusing the issue (by which time we had conveniently set it aside); if you do this one you probably don't want to try to dye the oil.
Things we talked about: One liquid can float on another liquid if they don't want to mix; oil is lighter than water, so it goes on top.
What Junie got out of it: Naked duck science! (In a tub of water, not the oil mix, if that wasn't clear. She asked for the duck and I figured, wait, why put on new clothes just to play with more water? It's warm... We've also added a new item, a cork, which turns out to float.)

Comments

[tirerim.livejournal.com]

Hm, there must be oil-soluble dyes. I have no idea what they are, though.

[psocoptera.livejournal.com]

Oil paint??

[rivka17.livejournal.com]

yes but bad idea in this context. btw oil paints mostly sink in water, a small bit of them will float on the surface if you slowly add only a tiny bit. You can use this to create a pretty colored pattern on the water that if you gently swipe a piece of paper across will result in neat marbled paper. A better choice would probably be to use colored oils (extra vergin olive oil = green) (toasted sesame oil = brown)