My guess is probably a lot given those wooden doors.
I don't see why this isn't a reasonable question for a chem exam. Maybe you chem guys can give us some insight. Here's the backstory and the question itself:
A chemistry professor whose exam question asked students to calculate the lethal dose of a poisonous gas used in Nazi gas chambers during the Holocaust has taken a leave of absence. Middlebury College in Vermont said that it's investigating under the terms of its faculty misconduct policy.
'This inexplicable failure of judgment trivializes one of the most horrific events in world history, violates core institutional values, and simply has no place on our campus,' wrote Middlebury President Laurie Patton last week. 'We expect our faculty to teach and lead with thoughtfulness, good judgment, and maturity. To say we have fallen short in this instance is an understatement.'
The question posed by Byers asked students to calculate how much poison it would take for them to create a lethal dose of hydrogen cyanide, the deadly chemical mixture used on Jewish people in the Nazi gas chambers during the Holocaust. 'Hydrogen cyanide is a poisonous gas, which Nazi Germany used to horrific ends during The Holocaust,' Byers wrote, according to Middlebury Campus.
'The lethal dose for humans is approximately 300. mg of HCN gas per kilogram of air when inhaled... If a room measured [redacted] ft. what mass of air would it have in g if the density fo the air [redacted] [Celsius] (room temperature) is [redacted]?' The exam also instructed students to, 'Calculate the g of HCN that would give a lethal dose in the above room.'
Archived Daily Fail article
Non-archivable local Faux News article
Archived CBS Jews article
Zyklon B was more expensive to make than crating in a more pure form of hydrogen cyanide(s). And even hydrogen cyanide in pellet form is not something anyone would legitmately try and genocide a group of people with. If you want to kill a bunch of people quick and easy, displace oxygen in the tanks. No unnecessary, messy, hazardous chemicals involved.Llet's not pretend like Germans weren't the world leaders in engineering at the time.
You know, if i were a "nasty nazi" looking for efficiency solutions for my freedom labor camp, I would probably experiment with delousing entire groups of people at one go - so, I would like to know the lethal dosage of this delousing agent so that I can be sure not to exceed it. I don't want to kill off my labor but I do want to kill the lice they carry.
Honestly, the whole gas thing is so stupid and makes no sense. There are much simpler and cheaper ways to kill people. I can't believe people still believe this nonsense.
But you guys are the experts, can you calculate this for us? Or give us even a rough estimate?
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EdSnowden ago
10x10x10 room for ease of calculation is 1,000 cubic feet
1,000 cubic feet of air is approximately 36.68 kilos in weight.
300mg/kilo breathed air lethal dose means you’d need just over 11,000mg, or 11g of zyklon b.
KILLtheRATS ago
We also need to figure out how long it takes to become toxic to people. I always understood it was 15 hours
snafu ago
Just commenting from a biological perspective, but HCN kills pretty quickly (within minutes). The reason is because of how it works. Basically, Cyanide works by inhibiting an enzyme called Cytochrome C, which is required to produce ATP (the main energy molecule used by cells) in the mitochondria (the power center of the cell). If you ingest cyanide, the molecule has to travel through the body (which dilutes it) and basically causes damage everywhere. If you breathe it however, the cyanide does enter the blood stream and does cause non-specific damage, but it mainly kills the lung cells. As the lung cells start dying you suffocate, which is mainly how it kills in gas form. That is much more efficient as you need a lot less as you have the dilution effect like when you ingest it.
KILLtheRATS ago
Is the concentration of cyanide in z-d enough to work as fast at pure cyanide? If it was only a portion, would it not take time to build up in the bodies. I was also told that the concentration need for death could not occur without hermetically sealed doors and a specific humidity. Can you speak on this? Also what is the lifespan of cyanide on concrete? Could it not be tested?
snafu ago
Just to clarify, I'm only talking about this from a chemistry/industrial process perspective, not anything else. I'm just going to share my knowledge without stating any opinion, and this is more relevant to anyone that works in a lab or does any kind of industrial chemistry as a lot of processes can produce toxic gas and you might not even know it until it's too late. With that said, I'm no expert (just have some background in it, but it's not my career) so if anyone actually does this for a living and I'm wrong about something please chime in.
Basically, as I understand it, z-d doesn't contain cyanide, rather it evolves (chemistry term, not the biological term) HCN (cyanide gas) when exposed to something (water? I forget). HCN is then breathed in, and in the body the hydrogen is stripped (which it's an acidic proton, so it happens readily) and turns into CN- (actual cyanide). @ChaoticNeutral 's calculation is actually an overestimation as his calculation is based on the amount of z-d that would be needed to cause a high enough concentration of CN- in the body to be a lethal dose. However, that's not how HCN kills. You have to remember that you're breathing it in and it kills your lung cells very fast, so you die from suffocation long before there is enough in your body to constitute a lethal dose. The concentration in the air that's needed is going to be much smaller because of how quickly destroys your lungs. I can't say what concentration is needed, but the calculation above is an upper bound, and in practice the amount needed is going to be much lower (the 9g calculated above is already a very tiny amount).
With regards to the doors, that's not really true (again from a chemistry perspective). Without active ventilation it's definitely possible to build up enough gas (of any type) to cause death as even if it's not sealed as there isn't going to be enough air flow to remove the gas. Gas diffusion is relatively slow, and would be much slower than the rate of HCN production (meaning the concentration will increase). In a lab, you'd have something called a 'hood', which is basically a box with an opening, but inside the box is a vacuum pump that actively sucks in air and puts in through a filter. This causes a negative pressure so air flows into the hood, and the chemist is protected from any gaseous byproducts as the box is actively ventilated. If that pump is off (and the hood is open) it's definitely possible to be harmed/killed by any toxic byproducts.
With regards to the lifespan of CN-, I don't have any numbers, but if I remember my chemistry correctly it should have a very low lifespan because it should be really reactive. CN- is two free electrons on a Carbon, which is triple bonded with a Nitrogen. Two electrons on a Carbon is called a Carboanion, which iirc are very very reactive. Basically they want to bind to anything they can, and would quickly be undetectable.
ChaoticNeutral ago
I do agree with everything you’ve stated. I was doing the calculation off of the instantly lethal inhalation dose listed in the SDS. Which means one breath should be lethal. I assume that it is much higher than the body tissue dose necessary to be lethal. People hear 9 grams and think ‘that’s so much’. Nope, not really. Also, Lewis, as in “Lewis acids and bases” was killed by cracked glassware while using HCN in a reaction.
You are also correct on the lifetime of CN-. It is a very reactive species.