Colors in Chem

Test for carbonate, (CO3-²)

Test for carbonate, (CO3-²)

Test: add dilute acid, then test for carbon dioxide gas

Results: effervescence, carbon dioxide produced

Test for chloride, Cr [in solution]

Test: acidify with dilute nitric acid, then add aqueous silver nitrate

Results: white ppt

Test for bromide, Br [in solution]

Test: acidify with dilute nitric acid, then add aqueous silver nitrate

Results: cream ppt

Test for iodide, I [in solution]

Test: acidify with dilute nitric acid, then add aqueous silver nitrate

Results: yellow ppt

Test for nitrate, NO3-, [in solution]

Test: add aqueous sodium hydroxide, then aluminium foil; warm carefully

Results: ammonia produced, pungent smell and turns damp litmus paper blue

Test for sulfate, SO, [in solution]

Test: acidify with dilute nitric acid, then add aqueous barium nitrate

Results: white ppt

Test for sulfite, SO2

Test: add a small volume of acidified aqueous potassium manganate(VII)

Results: the acidified aqueous potassium manganate(VII) changes from purple to colourless

Test for aluminium, Al3+

Test: aqueous sodium hydroxide

Results: white ppt, soluble in excess, giving a colourless solution

Test: aqueous ammonia

Results: white ppt., insoluble in excess

Test for ammonium, NH

Test: aqueous sodium hydroxide

Results: ammonia produced on warming

Test for calcium, Ca2+

Test: aqueous sodium hydroxide

Results: white ppt, insoluble in excess

Test: aqueous ammonia

Results: no ppt / very slight white ppt

Test for chromium(III), Cr3+

Test: aqueous sodium hydroxide

Results: green ppt, soluble in excess

Test: aqueous ammonia

Results: grey-green ppt, insoluble in excess

Test for copper(II), Cu2+

Test: aqueous sodium hydroxide

Results: light blue ppt

Test: aqueous ammonia

Results: light blue ppt, soluble in excess, creating a dark blue solution

Test for Iron (II), Fe2+

Test: aqueous sodium hydroxide

Results: green ppt, insoluble in excess, ppt turns brown near surface

Test: aqueous ammonia

Results: green ppt, insoluble in excess, ppt turns brown near surface

Test for Iron (III), Fe3+

Test: aqueous sodium hydroxide

Results: red/brown ppt, insoluble in excess

Test: aqueous ammonia

Results: red/brown ppt, insoluble in excess

Test for zinc, Zn2+

Test: aqueous sodium hydroxide

Results: white ppt, soluble in excess, giving a colorless solution

Test: aqueous ammonia

Results: white ppt, soluble in excess, giving a colorless solution

Test for ammonia, NH3

Test: damp red litmus paper

Results: turns blue

Test for carbon dioxide

Test: limewater

Results: turns milky

test for chlorine, Cl2

Test: damp litmus paper

Results: bleaches

test for hydrogen

Test: lightened splint

Results: pops

test for oxygen

Test: glowing splint

Results: relights

test for sulfur dioxide, SO2

Test: aqueous potassium manganate (VII)

Results: turns from purple to colorless

Flame test for lithium ion

red flame

Flame test for sodium ions

yellow flame

Flame test for potassium

lilac flame

Flame test for barium

light green flame

Flame test for copper (II)

blue-green flame

Colors for methyl orange indicator

Acid: red

Neutral: orange

Alkaline: yellow

Colors for litmus indicator

Acid: red

Neutral:

Alkaline: blue

Colors for phenolphthalein indicator

Acid: colorless

Neutral: colorless

Alkaline: pink

Colors for thymolphthalein indicator

Acid: colorless

Neutral: colorless

Alkaline: blue

Colors for universal indicator

PH

0-3:

• red

4-6:

• orange

7:

• green

8-11:

• blue

12-14:

• purple