Talk:Methane clathrate

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Contents 1 Natural gas clathrate? 2 Eh Value for Methanogenesis 3 Dodecahedral 4 Reservoir Size 5 Spoiler award granted for MC in popular fiction section! 6 A solid form of water?

[edit] Natural gas clathrate?

Since it also consists of other gases, similar to natural gas, should this be called "natural gas clathrate"? -- Kjkolb 03:17, 18 December 2005 (UTC)

[edit] Eh Value for Methanogenesis

Obviously an oversight, the Eh value given for methanogenesis was listed as < 400 mV. I have adjusted it to read between -350 mV -450 mV.

[edit] Dodecahedral

Dodecahedral refers to a solid with 12 faces, not 20 as is stated in the article. Should the value be 20 or 12? --71.227.190.111 20:51, 25 August 2006 (UTC)

The oxygen atoms of the water molecules form the vertices of the dodecahedron, not the faces. A dodecahedron has 20 vertices. —Keenan Pepper 21:48, 25 August 2006 (UTC)

I incorporated that information as it is not obvious to everyone, including me. Thanks for the information.Slicky 15:03, 20 January 2007 (UTC)

[edit] Reservoir Size

How does one convert from cu meters of Clathrate to tonnes of Carbon? Please help, I tried to validate the number and was out by three orders of magnitude for the 500-2500 Gigatonnes that is mentioned in this article. Frank van Mierlo 20:00, 5 January 2007 (UTC)

Let's see..

The density, δ, of the clathrate is δ = 0.9g/cm³ = 900 kg/m³ That gives that the mass of one m³ of clathrate is m = 900 kg.

m = M*n M = the molar mass of clathrate, n = the number of moles in one m³ M = 1(0.35*12+0.65*13+4*1)+ 5.75(16+2*1)= 120.15 g/mole = 0.12015 kg/mole (As there in each subunit of Clatherane is 1 mole CH₄ and 5.75 mole H₂O and the carbon consit to 35% of C¹² and 65% C¹³)

Thus the number of mole is n = m/M = 7490.63.. mole.

One mole clathrate has consist one mole of carbon --> there are 7490.63.. mole carbon in one m³ of clathrate. The weight of the carbon is m_C = n*M_C where M_C = (0.35*12 + 0.65*13) g/mole --> m_C = 102621.72..g= 102.62..kg

Conclusion: One m³ of clathrate hold 102.62..kg of pure carbon.

Given the estimates of 1×10¹⁵ to 5×10¹⁵ m³ clathrate this would give us between 1*10¹⁷ and 5*10¹⁷ kg in total. This translates to between 1*10¹⁴ and 5*10¹⁴ metric tonnes so eihter I or the one who wrote the article is out by 3 orders of magnitude. I would argue that I am right as 100 kilos of carbon per m³ seems reasonable and from there on it is virtually impossible to make any mistakes in the math. By the same reasoning there would have to be only 0.5 kg per m³ for the article to add upp, an absurdly low number. Either the total reserves of clathrate in m³ or the amount of carbon they hold are wrong.

All numbers taken from the article130.243.153.103 21:55, 28 May 2007 (UTC)

Clathrate deposits are typically only about 1% clathrane by volume. I think this is the bulk of your error. Dragons flight 22:36, 28 May 2007 (UTC)

That would explain most of the error. I'm still a litle high though, if only by twice the amount (between 1*10¹² and 5*10¹² metric tonnes), either way maybe it should be clearly stated that the deposits only contain ~1 % Clathrate?130.243.153.103 10:18, 29 May 2007 (UTC)

I concur that it is important to mention that only 1% by volume of a clathrate deposit is actually methane clathrate. I made a change to that effect. I was surprised to learn that it was! Kencomer (talk) 08:47, 24 December 2007 (UTC)

Isotopic ratio of average earth's carbon is C¹²/C¹³ 98.93/1.07. Where you get 35/65? So 1 m³ of methane clathrate hold only 900 * 12 / 120 = 90 kg of carbon.Qjim (talk) 20:43, 23 April 2008 (UTC)

[edit] Spoiler award granted for MC in popular fiction section!

I might get back to this after finishing the book...

[edit] A solid form of water?

What source says this is a solid form of water? Isn't it, instead, a sort of compound and not actually water anymore? --Blue Tie (talk) 22:58, 27 January 2008 (UTC)

Dunno the answer (not a chemist), but can tell you that water is "a sort of compound"; in fact, it is a compound. +ILike2BeAnonymous (talk) 23:47, 27 January 2008 (UTC)