Color in Chemistry

 

Flame Tests:

 

element               color

 

Cu                                            green

Li                                              red

K                                              violet

Sr                                             scarlet

Na                                            yellow

Ca                                           orange-red

Ba                                           yellow-green

Cs                                           deep violet

 

 

Ions

 

Ion                       Color

 

Mn ²⁺                                       pink

Cr ⁶⁺                                        orange

Cr ³⁺                                        dark green

MnO₄-                                       _purple

CrO₄^2-                                       yellow

Cr ₂O₇^2-                                    orange

Fe ²⁺                                        green

Fe ³⁺                                        yellow

Co^{2+  in} H2O                             pink

Co²⁺ in acid                              blue-purple

Cu²⁺                                         blue

Cu²⁺ anhydrous                         white

Ni²⁺                                          green

 

Precipitate           Colors (a sampling)

 

silver chloride                          white

silver sulfide                            black

lead chloride                            white

mercury chloride                      white

lead chromate                         yellow

mercury                                   black

aluminum hydroxide                white

iron (III) thiocyanate              blood red

copper(II) hydroxide               thick light blue

copper ammonia complex        thick dark blue

 

Halogens

 

chlorine    Cl^1-                          colorless

bromine    Br^1-                          brown

iodine        I^1-                           pink

 

Gases:

Cl₂                                            greenish yellow

I₂                                             purple

NO₂                                          colorless

N₂O₄                                        brown