 Taking this out of a comment and into a thread of its own. Is my heavy water still heavy? I have a bottle of 99% D2O, and it's hygroscopic, I don't know the history of it before I got it. It's about half full. It might have sucked in a lot of normal water from the air. 25 comments
This should be 6uL of pure 18 MOhm water. I suspect my pipette is slightly out of calibration.  @Dtl Relative density of 1.124? I'm gonna say your heavy water is still pretty pure. @azonenberg I'm impressed it came out so well, I had expected this to be contaminated with light water. I did a couple of other measurements of each of these, they came out the same to 2 decimal places. Must get the pipette calibrated again. Running the numbers we get 5.38 / 4.78 = 1.125 Or near as dammit 1.12 for the density of this heavy water. If it had absorbed much normal water it would be less dense, so I can assume that within the limits of a 10 min experiment on a Tuesday morning before my second cup of Tea, that this heavy water is pretty pure. @Dtl it's definitely going to make for an interesting 2nd cup of Tea. Does it impact the taste like hard/soft water?  @Dtl How do you measure such tiny volumes? We got to use pipettes a little in high school chemistry but microliters? That's so small, I'd imagine that surface tension would keep trying to pull your sample back into the container? Is that a thing? @uastronomer It's a disposable tip quite hydrophobic and we push the liquid out with a small amount of air.  @Dtl Silly question maybe but how are you ensuring that your samples (and presumably the pipette) are at 20 degrees C? @christineburns I'm not - the lab was definitely warmer than that, but everything was at the same temperature, so relative differences should be the same.  @labria I know - it doesn't seem right at all for this equipment, but it's the name for it.  @Dtl You could make an icecube and see if it sinks in water. In theory Deuterium is stable contrary to Tritium. If it was 99% pure ten years ago and the lid was tight, it still is 99% now. @Dtl I was going to say that you're venturing dangerously close to philosophy with those kinds of questions. |
Gregory's Server
The density of normal (pure) water is 1g / ml.
Heavy water is 1.12g / ml.
Let's check it. #Science