Color Reactions

Question 1

Acetate with Ethanol and sulfuric acid

Answer 1

Fruity odor of ethyl acetate

Question 2

Acetate with ferric chloride

Answer 2

brownish red ppt of basic acetates

Question 3

Aluminum with ammonia

Answer 3

Aluminum hydroxide white ppt

Question 4

Aluminum with aluminon reagent

Answer 4

Red lake

Question 5

Ammonium thiocyanate with ferric salts

Answer 5

Blood red complex of Ferric thiocyanate

Question 6

Ammonium thiocyanate with acidic cobalt solution

Answer 6

Beautiful blue Cobalt thiocyanate

Question 7

Arsenates with silver nitrate

Answer 7

Chocolate brown ppt

Question 8

Arsenites with silver nitrate

Answer 8

Yellow ppt

Question 9

Arsenates with ammonium molybdate

Answer 9

Yellow ppt

Question 10

Magnesia Mixture with Arsenites

Answer 10

No Reaction; Differentiating test for arsenates and arsenites

Question 11

Borates with sulfuric acid and methanol

Answer 11

green bordered flame

Question 12

Borates with turmeric paper; addition of NaOH results to

Answer 12

Orange; Olive green (NaOH)

Question 13

Bromine with carbon tetrachloride

Answer 13

orange color

Question 14

Carbonate with acidic aqueous solutions

Answer 14

effervescence

Question 15

Carbonate with phenolphthalein

Answer 15

red color; differentiating test with bicarbonate (colorless)

Question 16

Chloride with silver nitrate

Answer 16

white curdy ppt soluble in ammonia, insoluble in nitric acid

Question 17

Citrate with calcium chloride/hydroxide

Answer 17

No ppt or white ppt and dissolves on cooling

Question 18

Composition of Denige’s Reagent

Answer 18

pyridine and acetic anhydride (3:1)

Question 19

Denige’s Reagent with Citrate

Answer 19

Carmine Red

Question 20

Denige’s Reagent with Tartrate

Answer 20

Emerald green

Question 21

Chromium with NaOH

Answer 21

Grayish Green slug –> dissolves in excess reagent

Question 22

Cobalt with NaOH

Answer 22

Blue Cobalt Hydroxide –> Turning Olive Green –> Turning Rose Red

Question 23

Cobalt with potassium nitrite and acetic acid

Answer 23

Yellow ppt of cobaltinitrite

Question 24

Cobalt with alpha-nitroso-beta-napthol

Answer 24

Brown ppt

Question 25

Nickel with alpha-nitroso-beta-napthol

Answer 25

Red Brown ppt

Question 26

Nickel with dimethylglyoxime

Answer 26

Bright red crystalline ppt insoluble in ammonia

Question 27

Copper with iron in HCl

Answer 27

Red deposits on iron

Question 28

Copper with Ferrocyanide

Answer 28

Red brown ppt which turns blue with ammonia (formation of cupric ammonium complex)

Question 29

Iodide with chlorine or potassium permanganate

Answer 29

violet color

Question 30

Iodide with sulfuric acid and HOT Oxalic acid or COLD Sodium Bisulfite

Answer 30

Decolorization

Question 31

Cyanate with cobalt acetate

Answer 31

Azure blue crystals

Question 32

Phosphate with silver nitrate

Answer 32

Yellow ppt

Question 33

Phosphate with ammonium molybdate

Answer 33

Canary Yellow ppt (Ammonium Phosphomolybdate)

Question 34

Salicylate with ferric chloride

Answer 34

violet color

Question 35

Salicylate with acid

Answer 35

white ppt of salicylic acid

Question 36

Silver with HCl

Answer 36

white curdy ppt of AgCl

Question 37

Thiosulfate with HCl

Answer 37

Thiosulfuric acid which readily decomposes to Sulfur (Yellow ppt)

Question 38

Thiosulfate with Ferric chloride

Answer 38

dark violet solution which disappears immediately

Question 39

Zinc with hydrogen sulfide

Answer 39

white ppt of zinc sulfide

Question 40

Saccharin in Fluorescein Test (resorcinol + sulfuric acid + excess NaOH)

Answer 40

Fluorescent green liquid