Kemija - 2017. ljeto, 38.

A. ${\mathrm{N}\mathrm{H}}_4{}^{+}\backslash mathrm\{NH\}\_\{4\}\{\; \}^\{+\}$

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

C. ${\mathrm{H}\mathrm{C}\mathrm{O}}_3^{-}\backslash mathrm\{HCO\}\_\{3\}^\{-\}$

D. ${\mathrm{C}\mathrm{H}}_3{\mathrm{C}\mathrm{O}\mathrm{O}}^{-}\backslash mathrm\{CH\}\_\{3\}\; \backslash mathrm\{COO\}^\{-\}$