Kemija - 2014./15. jesen - 31.

A. ${\mathrm{P}\mathrm{O}}_4{}^{3-}\backslash mathrm\{PO\}\_\{4\}\{\; \}^\{3-\}$

B. ${\mathrm{H}}_3{\mathrm{O}}^{+}\backslash mathrm\{H\}\_\{3\}\; \backslash mathrm\{O\}^\{+\}$

C. ${\mathrm{H}}_3{\mathrm{P}\mathrm{O}}_4\backslash mathrm\{H\}\_\{3\}\; \backslash mathrm\{PO\}\_\{4\}$

D. ${\mathrm{H}}_2{\mathrm{P}\mathrm{O}}_4{}^{-}\backslash mathrm\{H\}\_\{2\}\; \backslash mathrm\{PO\}\_\{4\}\{\; \}^\{-\}$