Kemija - 2009./10. ljeto - 19.

${\mathrm{N}\mathrm{a}}_2{\mathrm{C}\mathrm{O}}_3\cdot {\mathrm{H}}_2\mathrm{O}\backslash mathrm\{Na\}\_\{2\}\; \backslash mathrm\{CO\}\_\{3\}\; \backslash cdot\; \backslash mathrm\{H\}\_\{2\}\; \backslash mathrm\{O\}$

${\mathrm{N}\mathrm{a}}_2{\mathrm{C}\mathrm{O}}_3\cdot 5{\mathrm{H}}_2\mathrm{O}\backslash mathrm\{Na\}\_\{2\}\; \backslash mathrm\{CO\}\_\{3\}\; \backslash cdot\; 5\; ~\backslash mathrm\{H\}\_\{2\}\; \backslash mathrm\{O\}$

${\mathrm{N}\mathrm{a}}_2{\mathrm{C}\mathrm{O}}_3\cdot 10{\mathrm{H}}_2\mathrm{O}\backslash mathrm\{Na\}\_\{2\}\; \backslash mathrm\{CO\}\_\{3\}\; \backslash cdot\; 10~\; \backslash mathrm\{H\}\_\{2\}\; \backslash mathrm\{O\}$

${\mathrm{N}\mathrm{a}}_2{\mathrm{C}\mathrm{O}}_3\cdot 2{\mathrm{H}}_2\mathrm{O}\backslash mathrm\{Na\}\_\{2\}\; \backslash mathrm\{CO\}\_\{3\}\; \backslash cdot\; 2~\; \backslash mathrm\{H\}\_\{2\}\; \backslash mathrm\{O\}$