History factoids which are largely unknown

Quote: JimRockford

The HFCs and HCFCs being used as replacements contain Fl and or Cl.

Fl is not a symbol for an element :)

The one most important fact about chemistry is that compounds have chemical and physical properties different from those of their constituent elements. Take water. As a compound it can put out many sorts of fires. As elements, oxygen facilitates combustion and hydrogen is a very good fuel.

But fluorine is a rather inconvenient element. you need some of it in small amounts, but past that it's poisonous. In concentration it can be very dangerous. Gasses are no less stable than solids or liquids, but since they float in the atmosphere, they have more opportunity to react with something and break down.

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I'm no chemist, but it this seems like a prety obscure mechanism.

No one will ever know in advance what all possible consequences from a chemical compound are. There's a reference book for organic chemistry, I forget tis name, that lists the chemical properties of many organic compounds. It's more like an overgrown encyclopedia, spanning lots of volumes, than what people often think of as a book (I suppose it fits in a phone now...)

But it's easy to see that poisonous, dangerous, highly reactive elements can be problematic if their very stable compound breaks down.

In the 40s chemists at the Manhattan Project did a lot of work with fluorine, because it was needed to separate uranium isotopes. Most uranium is 238, but a nuke needs a lot of U-235. Uranium forms a gas when it reacts with fluorine, I think uranium hexafluoride. That can be manipulated in such a way that you can sort out molecules by mass.

U-238 is mildly radioactive, but not particularly dangerous (unlike any plutonium isotope). What had to be handled with care was the fluorine.

No astronaut in an American spaceship has ever died in space. Challenger and Columbia both met their end inside the atmosphere. Apollo I caught fire on the launch pad.

Quote: Nareed

Fl is not a symbol for an element :)

The one most important fact about chemistry is that compounds have chemical and physical properties different from those of their constituent elements. Take water. As a compound it can put out many sorts of fires. As elements, oxygen facilitates combustion and hydrogen is a very good fuel.

But fluorine is a rather inconvenient element. you need some of it in small amounts, but past that it's poisonous. In concentration it can be very dangerous. Gasses are no less stable than solids or liquids, but since they float in the atmosphere, they have more opportunity to react with something and break down.



No one will ever know in advance what all possible consequences from a chemical compound are. There's a reference book for organic chemistry, I forget tis name, that lists the chemical properties of many organic compounds. It's more like an overgrown encyclopedia, spanning lots of volumes, than what people often think of as a book (I suppose it fits in a phone now...)

But it's easy to see that poisonous, dangerous, highly reactive elements can be problematic if their very stable compound breaks down.

In the 40s chemists at the Manhattan Project did a lot of work with fluorine, because it was needed to separate uranium isotopes. Most uranium is 238, but a nuke needs a lot of U-235. Uranium forms a gas when it reacts with fluorine, I think uranium hexafluoride. That can be manipulated in such a way that you can sort out molecules by mass.

U-238 is mildly radioactive, but not particularly dangerous (unlike any plutonium isotope). What had to be handled with care was the fluorine.

Is the HFC refrigerant R134 currently being used by all auto manufacturers a disaster in the making since it has F?

Quote: JimRockford

Is the HFC refrigerant R134 currently being used by all auto manufacturers a disaster in the making since it has F?

Maybe.

I'm sure, though, it has been more thoroughly researched than the original CFCs were.