Email or username:

Password:

Forgot your password?
Top-level
Dr David Mills

This should be 6uL of pure 18 MOhm water. I suspect my pipette is slightly out of calibration.
This should read 6 mg. #science

14 comments
Dr David Mills

Now with 6uL of heavy water.
It's heavier!
5.3791mg #science

Andrew Zonenberg

@Dtl Relative density of 1.124? I'm gonna say your heavy water is still pretty pure.

Dr David Mills

@azonenberg I'm impressed it came out so well, I had expected this to be contaminated with light water.

Dr David Mills

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.

#science

Ben Hardill

@Dtl it's definitely going to make for an interesting 2nd cup of Tea.

Does it impact the taste like hard/soft water?

Dr David Mills

@ben Wikipedia claims it tastes slightly sweet.

Allen Very Serious Versfeld

@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?

Dr David Mills

@uastronomer It's a disposable tip quite hydrophobic and we push the liquid out with a small amount of air.

Christine Burns MBE 🏳️‍⚧️📚⧖

@Dtl Silly question maybe but how are you ensuring that your samples (and presumably the pipette) are at 20 degrees C?

Dr David Mills

@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.

Go Up