Common formulae

Every block on this page is rendered at build time by invoking the asciichem gem. Source on the left; MathML output on the right. If you view the page source, you’ll see the same is what you’d type.

Water and simple molecules

H_2O

${\mathrm{H}}_2\mathrm{O}$

CO_2

$\mathrm{C}{\mathrm{O}}_2$

NaCl

$\mathrm{Na}\mathrm{Cl}$

CH_4

$\mathrm{C}{\mathrm{H}}_4$

Acids and bases

HCl

$\mathrm{H}\mathrm{Cl}$

H_2SO_4

${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$

HNO_3

$\mathrm{H}\mathrm{N}{\mathrm{O}}_3$

H_3PO_4

${\mathrm{H}}_3\mathrm{P}{\mathrm{O}}_4$

NaOH

$\mathrm{Na}\mathrm{O}\mathrm{H}$

Ca(OH)_2

$\mathrm{Ca}{\left(\mathrm{O}\mathrm{H}\right)}_2$

Ionic compounds

Na^+

${\mathrm{Na}}^{+}$

Cl^-

${\mathrm{Cl}}^{-}$

SO_4^2-

$\mathrm{S}{\mathrm{O}}_4^{2-}$

NO_3^-

$\mathrm{N}{\mathrm{O}}_3^{-}$

Ca^2+

${\mathrm{Ca}}^{2+}$

Isotopes — the headline semantic fix

^14C

${}^{14}\mathrm{C}$

^131I

${}^{131}\mathrm{I}$

^238U

${}^{238}\mathrm{U}$

^3H

${}^3\mathrm{H}$

The prefix isotope binds to the atom. See Atoms for the full story.

Coordination complexes

[Fe(CN)_6]^4-

$\left[\mathrm{Fe}{\left(\mathrm{C}\mathrm{N}\right)}_6\right]\text{^4-}$

[Co(NH_3)_6]^3+

Install the asciichem gem to see this rendered.

[PtCl_4]^2-

$\left[\mathrm{Pt}{\mathrm{Cl}}_4\right]\text{^2-}$

Stoichiometric coefficients

2H_2O

$2{\mathrm{H}}_2\mathrm{O}$

3H_2

$3{\mathrm{H}}_2$

C_6H_12O_6

${\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6$

Reactions

2H_2 + O_2 -> 2H_2O

$2{\mathrm{H}}_2+{\mathrm{O}}_2\to 2{\mathrm{H}}_2\mathrm{O}$

N_2 + 3H_2 <=>[Fe][400°C] 2NH_3

${\mathrm{N}}_2+3{\mathrm{H}}_2\underset{\mathrm{Fe}}{\overset{\text{400°C}}{\rightleftharpoons }}2\mathrm{N}{\mathrm{H}}_3$

CH_4 + 2O_2 -> CO_2 + 2H_2O

$\mathrm{C}{\mathrm{H}}_4+2{\mathrm{O}}_2\to \mathrm{C}{\mathrm{O}}_2+2{\mathrm{H}}_2\mathrm{O}$

Bonds in linear notation

H-O-H

$\mathrm{H}-\mathrm{O}-\mathrm{H}$

H_2C=CH_2

${\mathrm{H}}_2\mathrm{C}=\mathrm{C}{\mathrm{H}}_2$

HC#CH

$\mathrm{H}\mathrm{C}\equiv \mathrm{C}\mathrm{H}$

Electron configurations

1s^2 2s^2 2p^6

$\text{1s^2 2s^2 2p^6}$

1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10

$\text{1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10}$

Verify locally

gem install asciichem
asciichem convert -i "2H_2 + O_2 -> 2H_2O" -t mathml
asciichem convert -i "2H_2 + O_2 -> 2H_2O" -t latex
asciichem roundtrip -i "2H_2 + O_2 -> 2H_2O"