Density of LN2 as it warms up

[K404]

Kinda weird question. I had my dewars filled but have been pretty slow in getting through them. I keep a tally of my useage so I don't accidentally try something big with only 3L left or something stupid like that. My tally is pretty tight but the weight of the dewars doesn't follow the tally.

As LN2 "warms up"... what happens to its density? As it approaches -196/ boiling point does it gain weight?




Cheers!

[Q56_Monster]

One mole of N2 equal 14grams. And the conservation of matter would suggest gaining weight, or mass, is impossible. When it boils off into a gaseous state, it expands, but keeps it's same mass (weight here on earth). I would think if you had a dewar strong enough to contain all the boiled off N2, it would weight the same as when you first filled it with LN2. But what do I know, I'm a finance guy....been a long time since college chemistry, lol.

[K404]

I bombed horrifically at Chemistry I have no idea why the numbers don't add up here. According to the scales, I have litres more than I expected to. I'm benching tonight, lets see what happens