5 Steps to a 5 AP Chemistry

Ligand Formula(abbreviation) Ligand name

Cyanide ion CN− cyano

Fluoride ion F− fluoro

Hydride ion H− hydrido

Hydroxide ion OH− hydroxo

Iodide ion I− iodo

Nitrite ion NO 2 − nitrito

Oxalate ion C 2 O 42 − oxalato

Sulfide ion S^2 − thio

Thiocyanate ion SCN− thiocyanato

Ammonia NH 3 ammine

Ethylenediamine en ethylenediamine

Water H 2 O aqua

Colors of Common Ions in Aqueous Solution

Most common ions are colorless in solution, however, some have distinctive colors. These

colors have appeared in questions on the AP exam.

Fe^2 +and Fe^3 + various colors

Cu^2 + blue to green

Cr^2 + blue

Cr^3 + green or violet

Mn^2 + faint pink

Ni^2 + green

Co^2 + pink

MnO 4 − dark purple

CrO 42 − yellow

Cr 2 O 72 − orange

Common Ions  355