Organic Tests and Methods

Question 1

(1) Appearance and smell

Answer 1

Observe colour and smell cautiously

Question 2

(2) Miscibility or solubility in water

Testing for polarity of liquid

Answer 2

Add a few cm3️⃣ of the liquid to deionised water in a test tube

Question 3

(3) Combustion

Testing for carbon content

Answer 3

Place a few drops of the liquid on a watch glass and ignite with a lit splint

Question 4

(4) Bromine water

Testing for presence of C=C bond

Answer 4

Add a few cm3️⃣ of bromine water to the liquid or solution in the test tube

Question 5

(5) Silver nitrate solution with ethanol

Testing for presence of halogen atoms in a haloalkane

Answer 5

Add 1cm3️⃣ of the haloalkane to a few cm3️⃣ of ethanol

Add silver nitrate solution and warm in a water bath

Question 6

(6) Phosphorus pentachloride

Testing for OH group

Answer 6

Add a few crystals of phosphorus pentachloride to a few cm3️⃣ of the liquid
Test any gas released with a glass rod dipped in concentrated ammonia solution

Question 7

(7) Acidified potassium dichromate

Testing for primary/secondary alcohol as opposed to a tertiary alcohol

Answer 7

Mix a few cm3️⃣ of the liquid or solution with acidified potassium dichromate solution in a test tube and warm in a water bath

Question 8

(8) Iodoform test

Testing for secondary alcohol

Answer 8

Add sodium hydroxide solution and iodine solution to a few cm3️⃣ of the liquid, and warm

Question 9

(9) Sodium carbonate/hydrogencarbonate

Testing for COOH group, or carboxylic acid

Answer 9

Add half a spatula measure of solid sodium carbonate/hydrogencarbonate to a few cm3️⃣ of the liquid or solution

Question 10

(10) Magnesium

Testing for COOH group, or carboxylic acid

Answer 10

Add a strip of magnesium ribbon to a few cm3️⃣ of the liquid