Scientific explanation of how Potassium granades work

[darklizard45]

As we know potassium granades are capable of generating a decently big explosion and are praised and hated because of that
But how does this reaction actually works?
Here is the equation:

2K + 2H2O -> 2K(OH) + H2

If you are unable to understand what this equation says I can easily translate it to you:

The potassium metal reacts very rapidly with water to form a colourless solution of potassium hydroxide (KOH) and hydrogen gas (H2). The resulting solution is basic because of the dissolved hydroxide. The reaction is exothermic. Early in the reaction, the potassium metal becomes so hot that it catches fire and burns with a characteristic pale lilac colour.
Of course as you can see below the reaction is not strong enough to cause a significant explosion instead it just generates a brief flash and A LOT of smoke. So it could work more like a smoke granade rather than a explosive granade.


https://www.youtube.com/watch?v=04hG3eUY2ME
https://www.youtube.com/watch?v=Jy1DC6Euqj4

[darklizard45]

A chemical reaction, in order to cause a significant explosion, it has to have one of the major properties an explosion needs.
It has to expand very rapidly

[Toroic]

If you put something that expands very rapidly in a confined space, you get an explosion.

[darklizard45]

If you put something that expands very rapidly in a confined space, you get an explosion.

Aww... jeeez now we need a physicist to explain how much energy an explosion made from the mixture of 1kg of pottassium and 1L of water would make... in a confined space of course...

[Toroic]

Aww... jeeez now we need a physicist to explain how much energy an explosion made from the mixture of 1kg of pottassium and 1L of water would make... in a confined space of course...

Well, K has a molecular weight of about 39 grams per mol, so that would be 25.64 mol of potassium.

According to this website http://www.chemguide.co.uk/inorganic/gr ... cth2o.html it looks like potassium and water release 196 kJ/mol when they react, so we'd get 5025kJ of energy being released.

According to this chart https://en.wikipedia.org/wiki/TNT_equivalent one gram of tnt releases 4.184kJ of energy, so we'd have about 1200g, or 1.2kg of TNT equivalent.

Here's a video of what is supposedly 1kg of tnt being blown up.

https://www.youtube.com/watch?v=QUSff_JGyqw

Granted, this is napkin math from someone who passed organic chemistry II with a C.

[darklizard45]

The more you learn boys

[YungCuz]

did i just get scienced

[LordLoko]

did i just get scienced

[Crab_Spider]

Wait shouldn't Sodium and also produce the same reaction in water due to it being an Alkali metal?

[darklizard45]

Wait shouldn't Sodium and also produce the same reaction in water due to it being an Alkali metal?

Yes it should... but for some reason in game that doesn't happen

[Crab_Spider]

Yes it should... but for some reason in game that doesn't happen

Wait, lithium should also undergo the same reaction, it's as if we glossed over the chemistry and went with the properties everyone knows. At the very least we could've used Francium as the reactive agent.