This Molecule Has Saved Billions of Lives, How Do We Make It Without Killing Ourselves?

Fritz Haber was brilliant. His discovery of the Haber-Bosch process to produce ammonia from the air was a miracle, allowing for the vast production of fertilizer which lead to our ability to feed the billions of people on our planet, rightfully earning Haber an Nobel Prize.

Yet, he also produced chlorine gas and conducted experiments that eventually lead to the development of pesticide gases such as Zyklon B, used to kill millions of Jewish people in Nazi concentration camps. I'm not sure where Haber would have fallen when his soul was weighed upon his passing from this Earth, but I know we couldn't feed as many as we feed without the Haber-Bosch process.

Today's SciShow video explains how the Haber-Bosch process produces carbon dioxide and some of the alternative processes that chemists are exploring that wouldn't produce carbon dioxide along the way.

Opening a Soda on the Ocean Floor

Chris Hadfield is among the best of us.

He's a fickin' astronaut, a pretty nifty quitar player, a hell of a pilot, a great science communicator, the father of an interesting YouTuber, and a good sport.

In this video, Chris doesn't do a lick of science explaining, but he does demonstrate the fact that if you're going to shake up a soda can and immediately open it, you'd best be under double atmospheric pressure at the bottom of the ocean.

To fill in what Chris doesn't explain, the fizzing is largely a result of this equilibrium...

H₂CO_{3 (aq)}  ⇌   H₂O _(l) + CO_{2 (g)}

At normal atmospheric pressure that CO₂ pressure is low, so the reaction shifts to the right until it reaches equilibrium and your pop is flat. Allowing the pressure to build up in a sealed container - keeping the coke bottle closed up - stops this from progressing because eventually Q = K. So does cooling down the tonic container because the reaction is exothermic and endothermic reactions (the reverse reaction, keeping the gas dissolved in the solution as carbonic acid) are favored at colder temperatures.

But at the bottom of the ocean, there's apparently a high enough CO₂ pressure in the atmosphere that the soda doesn't immediately fizz up.

Hiding a Nobel Prize From the Nazis

So much chemistry here.

Great explanation of a famous story of Neil Bohr's lab - particularly George de Hevesy - dissolving two gold Nobel prize medals to hide them from the Nazis...and then precipitating the gold back out of solution a decade or so later once the Nazis had been defeated.

It's a great story, and the science - full d-shells, equilibrium, Le Chatelier's principle - is outstanding. The story itself is better told in this NPR post from Same Kean's The Disappearing Spoon book, but Kean doesn't go into the science as well as Hank Green does here.