Kemija - 2010./11. jesen - 35.

A. ${\mathrm{H}}_2{\mathrm{P}\mathrm{O}}_4{}^{-}\mathrm{i}{\mathrm{H}\mathrm{P}\mathrm{O}}_4{}^{2-}\backslash mathrm\{H\}\_\{2\}\; \backslash mathrm\{PO\}\_\{4\}\{\; \}^\{-\}\; ~\backslash mathrm\{i\}\; ~\backslash mathrm\{HPO\}\_\{4\}\{\; \}^\{2-\}$

B. ${\mathrm{H}}_2{\mathrm{P}\mathrm{O}}_4{}^{-}\backslash mathrm\{H\}\_\{2\}\; \backslash mathrm\{PO\}\_\{4\}\{\; \}^\{-\}$ i  ${\mathrm{H}}_3{\mathrm{O}}^{+}\backslash mathrm\{H\}\_\{3\}\; \backslash mathrm\{O\}^\{+\}$

C. ${\mathrm{H}}_2\mathrm{O}\backslash mathrm\{H\}\_\{2\}\; \backslash mathrm\{O\}$  i  ${\mathrm{H}}_3{\mathrm{O}}^{+}\backslash mathrm\{H\}\_\{3\}\; \backslash mathrm\{O\}^\{+\}$

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