# Tag Info

### Where does the energy in coal bonds come from?

Here's a nicely simplified description of the structure of coal: V.D Macromolecular Nature of Coals Coals are believed to be three-dimensionally cross-linked macromolecular networks containing ...
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### Where does the energy in coal bonds come from?

When the sun's energy was utilised to separate carbon and oxygen how can the coal bonds store it? You use the word 'utilised' as if this means the energy is used; it no longer exists. But energy ...

### Where does the energy in coal bonds come from?

Electrons around the nuclei of atoms exist in various energy states due to quantum mechanical principles. Due to these principles, they are confined to certain configurations (shells and orbitals). ...
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### Where does the energy in coal bonds come from?

Photosynthesis is a little like the reverse of burning The idea that chemicals or their bonds store energy needs some clarification. The storage is always relative to some other reachable arrangement ...
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### Where does the energy in coal bonds come from?

Indeed it's in some way counterintuitive to say that the sun's energy is 'stored' in the coal bonds. Energy never comes from breaking bonds, it is released when forming bonds. In the case at hand, the ...
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### Where does the energy in coal bonds come from?

As has been pointed out the energy comes in the form of visible light from the sun. The reaction written in summary or overview is $$\displaystyle \ce{2H2O \overset{light}\to O2 + 4H^+ + 4e^-}$$ \...
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### What makes a compound high or low energy and why does that relate to reactivity?

Stronger bonds make more stable compounds both kinetically and thermodynamically. Kinetically because bonds must be broken for reactions to happen. Thermodynamically because bonds must be formed. A ...
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1 vote

### Spontaneity criterion for phase transformations and chemical reactions

Spontaneity is simply a system not at equilibrium (this is regardless of direction) with a possible mechanism to reach equilibrium. Before getting upset note that reactions involving only standard ...
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### Spontaneity criterion for phase transformations and chemical reactions

Enthalpy $H$ is not a valid criterion for spontaneous reactions. Spontaneous reactions may be exothermic or endothermic. The famous reaction of $\ce{NaHCO3 + HCl}$ is endothermic, but it is ...
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### What scientific and technical challenges prohibit the industrial use of the Sabatier reaction?

The primary barrier to all related reactions is their economics There are a number of ways to produce useful synthetic hydrocarbons from various carbon-containing sources. The Sabatier reaction might ...
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