LaTex (6) Special Chemical Symbols

(3) Special symbols

1. Chemical bond

mhchem.js supports the representation of single-line chemical bonds, that is to say, it can represent simple physical/organic related chemical formulas and equations. However, chemical formulas containing structures such as branched chains/benzene rings cannot be written.

SyntaxDisplayDescription
\ce{C6H5-CHO}\(\ce{C6H5-CHO}\)heptanal
\ce{CH2=CH2}\(\ce{CH2=CH2}\)ethylene
\ce{CH#CH}\(\ce{CH#CH}\)acetylene

It is not difficult to see that the following chemical bonds are supported:

  • Single key: - (\(\ce{C-C}\))
  • double bond: = (\(\ce{C=C}\))
  • Triple key: # (\(\ce{C#C}\))

More complex chemical bonds:

SyntaxDisplay
\ce{A\bond{~}B\bond{~-}C}\(\ce{A\bond{~}B\bond{~-}C}\)
\ce{A\bond{~--}B\bond{~=}C\bond{-~-}D}\(\ce{A\bond{~--}B\bond{ ~=}C\bond{-~-}D}\)
\ce{A\bond{...}B\bond{....}C}\(\ce{A\bond{...}B\bond{....}C }\)

2. Complexes

Use . to represent "·" in the complex.

SyntaxDisplayDescription
\ce{MgSO4.7H2O}\(\ce{MgSO4.7H2O}\)Magnesium sulfate heptahydrate
\ce{KCr(SO4)2*12H2O}\(\ce{KCr(SO4)2*12H2O}\)Potassium chromium sulfate dodecahydrate (chromium alum)
\ce{CaSO4.1/2H2O + 1\!1/2 H2O - CaSO4.2H2O}\(\ce{CaSO4.1/2H2O + 1\!1/2 H2O - CaSO4.2H2O}\ )Hydration of calcium sulfate

3, Precipitation symbol and gas scale

Use v for precipitation and ^ for gas.

SyntaxDisplayDescription
\ce{Ba^2+ + SO4^{2-} = BaSO4(v)}\(\ce{Ba^2+ + SO4^{2-} = BaSO4(v)}\)Barium Sulfate Precipitation
\ce{2H2O2 \xlongequal{MnO2} 2H2O + O2(^)}\(\ce{2H2O2 \xlongequal{MnO2} 2H2O + O2(^)}\)Decomposition of hydrogen peroxide

It is worth noting that \xlongequal is used here to represent the long equal sign, and the autoload-all.js plug-in needs to be introduced.
The specific syntax of the equal sign is: \xlongequal[content below the line]{content above the line}.

4. Arrow

SyntaxDisplay
\ce{A ->B}\(\ce{A ->B}\)
\ce{A <- B}\(\ce{A <- B}\)
\ce{A <=> B}\(\ce{A <=> B}\)
\ce{A <=>> B}\(\ce{A <=>> B}\)
\ce{A <<=> B}\(\ce{A <<=> B}\)
\ce{A ->[{{}\atop x}] B}\(\ce{A ->[{{}\atop x}] B}\)
\ce{A ->T[text above][text below] B}$$\ce{A ->T[text above][text below] B}$$
\ce{A ->[{}\atop\ce{+H2O}] B}\(\ce{A ->[{}\atop\ce{+H2O}] B}\)

More arrow references:

LaTex Mathematical Formula (2) Common Symbols
https://blog.tsinbei.com/archives/929/

5, free radicals

SyntaxDisplayDescription
\ce{Cl*}\(\ce{Cl*}\)
\ce{{}*CH3}\(\ce{{}*CH3}\)Note the {} before *

6, brackets

SyntaxDisplayDescription
\ce{(NH4)2S}\(\ce{(NH4)2S}\)parentheses
\ce{[AgCl2]-}\(\ce{[AgCl2]-}\)square brackets
\ce{[\{(X2)3\}2]^3+}\(\ce{[\{(X2)3\}2]^3+}\)large parenthesis (requires slash escape)

7, thermochemical equation

Between the equation and the enthalpy change, you need to use \qquad to separate.

example:

LaTeX
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$$\ce{N2(g) + 3H2(g) -> 2NH3(g)} \qquad \Delta H_{\mathrm{f}}^\circ = \SI{-92.5}{kJ}$$

Rendering effect:

$$\ce{N2(g) + 3H2(g) -> 2NH3(g)} \qquad \Delta H_{\mathrm{f}}^\circ = {-92.5}{kJ}$$

Tip:
The above formula is beyond the screen of the mobile phone, so it is treated specially.

For super long formulas, you can add in the configuration

css
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.MathJax_Display {
     overflow-x: auto;
     overflow-y: hidden;
}

or

JavaScript
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MathJax.Hub.Queue(
     function ()
     {
         $('.MathJax_Display').wrap("<div class='overflow'></div>");
     }
);

Plus

css
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.overflow {
     overflow-x: auto;
     overflow-y: hidden;
}

references

Download:

Qingbei network disk
Link: https://pan.tsinbei.com/s/Q5uk
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LaTex (6) Special Chemical Symbols

https://blog.tsinbei.com/en/archives/674/

Author
Hsukqi Lee
Posted on

2022-12-13

Edited on

2022-12-13

Licensed under

CC BY-NC-ND 4.0

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