[Nihilist]

According to this chart, Calcium is higher in the reactivity series than Sodium. I asked my chemistry teacher about it but she couldn't explain it. Although there was a discussion about it on another board a while back no one could actually explain why. Can you?

[Mitch]

It just says that Calcium likes to form oxides more than Sodium does. Remember reactivity isn't some broad subject. Reactivity is specific per reaction. Sodium is more reactive than sodium when you place it in water, as a counter example.

[AWK]

Reactivity is a much complex problem than any chart can show - in any case reagent and condition should be specified, eg some metals react with elemental nitrogen (commonly considered as extremely unreactive) easier than with oxygen, stainless steel is resistat to action of oxygen anf acids but not for diluted solution od sodium hypochlorite, and so on.

[Limpet Chicken]

I have read that Ca is the reducing agent from hell, and that it will even reduce the compounds of cesium and rubidium to the metals...cesium thermite anybody? lol

[AWK]

It is not a net thermite reaction.
Boiling point of calcium is 1484 C (melting point 842 C), Rb - 688 C, Cs - 671 C.

When to melted salts of rubidium or cesium you add melted calcium, according to Le Chatelier-Brown principle vapours of cesium or rubidium are formed.

[Limpet Chicken]

EEP! sounds nasty if you happen to be anywhere near it when it goes off lol.

[jdurg]

Well, due to the intense reactivity of the alkali metals, these generation reactions take place in an enclosed chamber with an argon atmosphere.  Trying to generate pure sodium, potassium, rubidium, or cesium in an open atmosphere container would result in fires and explosions as it reacts with the nitrogen, oxygen, water, and various other components of natural air.  

[Limpet Chicken]

I might have to give this a go, it will certainly be an easier way to make sodium than standing over a can of fused  NaOH in air and zapping it with a car battery  as I have been doing recently

[Mitch]

This topic can not be answered. So, I'm locking it.