[gotovenus]

I am a writer doing research on a rocket scientist (loosely speaking) from 1927. He claimed, among many other things, that he had built a manned rocket to be powered, not by black powder or gasoline, but by "a slow explosive, the most powerful alkali-peroxide of sodium."

I am fairly sure this Rocketeer was a crank. But, i need an expert opinion on what he may have meant by "alkali-peroxide of sodium" . I can find no reference to this chemical and I suspect that it never existed at all. Keep in mind it was 1927. Can someone please comment.

(Sorry if this is in the wrong forum btw.)

thanks for reading
doug

[Arkcon]

I don't know what's absolutely wrong with the story.  But sodium peroxide is a well known chemical.  The name "alkali-peroxide of sodium" may have been an archaic name, some resources may connect them for you.  For example, every chemical sold has an MSDS, and it will often list all possible industry names for a chemical.  So that's one thing you can look at, if you need continuity for your historical paper.

[Big-Daddy]

There's no doubt if it's a "peroxide of sodium" that it is sodium peroxide, Na2O2.

That - and the fact that I've heard of H2O2 in conjunction with rockets - suggests to me that it is very much Na2O2 you're looking for. Let's also not neglect to mention that it is highly basic (a diprotic base, associating protons up to H2O2 in solution - if you don't know this then don't worry, it doesn't matter, the point is Na2O2 is very "alkaline").

Do you think maybe he meant "the most powerful alkali: peroxide of sodium"? Because there aren't more than one peroxides of sodium, and Na2O2 will be a strongly basic substance, though I don't know about "strongest alkali".

[gotovenus]

Thanks Akron and Big Daddy. Thanks Akron, I do believe the archaic name for the chemical may have thrown me and made it hard to find an exact reference. And Big Daddy , I do think that it is very possible that the newspapers of the time may have misprinted the chemical name and the Rocketeer may have meant alkali:peroxide of sodium. Thanks again.

So, H202 and Na202 are both considered profoundly base/alkaline chemicals. But, H202 is the one associated with rocket fuel.

[Arkcon]

Quickly browsing the Wikipedia article on rockets, over here:  http://en.wikipedia.org/wiki/History_of_rockets  you find out that primitive rockets have existed, in China, since Antiquity.  The concept of interplanetary rockets, going back to Goddard  (and other people who preceded him with theories if not practical application) started the concept of liquid fueled rockets, and multiple stages.  The benefit liquid fueled rockets provide is that you can save weight, by making only the engine strong enough to survive the reaction.  The solid fueled, manned rocket sounds pretty unlikely by comparison, although Goddard did propose those as well.

[billnotgatez]

http://en.wikipedia.org/wiki/Sodium_peroxide
http://en.wikipedia.org/wiki/Hydrogen_peroxide

The Hydrogen peroxide shows a pKa of 11.75
The Sodium peroxide does not list a pKa

I assume that is because it reacts violently with water

[discodermolide]

Have a read at this book. I'm not sure when it dates from but it is interesting.
http://library.sciencemadness.org/library/books/ignition.pdf

[Big-Daddy]

http://en.wikipedia.org/wiki/Sodium_peroxide
http://en.wikipedia.org/wiki/Hydrogen_peroxide

The Hydrogen peroxide shows a pKa of 11.75
The Sodium peroxide does not list a pKa

I assume that is because it reacts violently with water

Yes, a very strong reaction ... to form NaOH, which as we know is a strong base.

[Enthalpy]

Maybe he used sodium peroxide as an oxidizer - which it is. Then the alkali might be the fuel, mixed with peroxide prior to ignition, since both would be solids.

A reaction looking like Na₂+Na₂O₂  2Na₂O

While such a reaction is exothermic, it makes a really poor pair of propellants, especially because it produces little gas to expand and because Na₂O melts and boils too easily, preventing to release the reaction heat, but few people would have been aware of that in 1927.

Any hydrocarbon would be a better fuel than an alkali, but it was possible to ignore it in 1927.

And, well, Na₂O₂ is a poor oxidizer as well... Even worse than H₂O₂.

One more difficulty: for a stable flame, solid propellants need a so-called "pressure exponent" below 1, which isn't very common and would need to be checked for Na₂O₂. This exponent tells how the speed of the flame front reacts to pressure. Knowing that the combustion chamber's throat evacuates mass with a pressure exponent of 1, this (which depends essentially on the oxidizer) tells if both combine harmoniously, if you see what I mean.

Perchlorates use to have a pressure exponent well below 1 hence are used, chlorates consistently make boom (unless the atmospheric counterpressure stabilizes the speed), and nitrates... sometimes.