Expt.
12 : To identify the functional group present in the given organic
compound - I
Experiment Observations Inference
1. Test for unsaturation:
ALKALINE KMnO4 TEST (BAEYER’S TEST):
Dissolve a little of the given organic compound in about 2
ml of water or acetone in a test tube. Add 1–2 drops of Pink colour of KMnO4 An unsaturation is
alkaline solution of KMnO4 (1%) and shake the mixture. gets decolourised. present.
2. Test for carboxylic group:
SODIUM HYDROGENCARBONATE TEST: Brisk effervescence. Carboxylic group
Added a pinch of NaHCO3 to 0.2 ml of organic (R-COOH) is present.
compound in a test tube.
3. Test for phenolic group:
FERRIC CHLORIDE TEST:
Added 0.2 ml of organic compound to 2–3 ml neutral No green or violet Phenolic (Ar-OH)
FeCl3 solution in a test tube. colour obtained. group is absent.
4. Test for alcoholic group:
CERIC AMMONIUM NITRATE TEST:
Place about 1 ml of the given compound in a clean dry No pink or red colour
Alcoholic (R-OH)
test-tube, add a few drops of ceric ammonium nitrate
group is absent.
reagent and shake well.
5. Test for carbonyl group:
2, 4-DINITROPHENYL HYDRAZINE TEST (2, 4—
DNP TEST)
Carbonyl group is
Take 0.5 ml or 0.5 g of the given compound in a clean
No Orange-yellow ppt. absent or
dry test-tube, add rectified spirit until the compound
formed. Carboxylic acids do
just dissolves. Now add a few drops of 2, 4-
dinitrophenyl hydrazine solution. Cork the test-tube, not give this test.
shake the mixture and allow it to stand for 5 minutes.
6. Test for aldehydic group :
FEHLING’S TEST:
Take 1 ml each of Fehling’s solution A and B in a test
tube. Add 4–5 drops (or 0.2 g) of the given organic No red precipitate Aldehyde (R-CHO) is
compound and warm the test tube in hot water bath for absent.
4–5 minutes.
7. Test for Ketonic group :
m-DINITROBENZENE TEST:
Place 0.5 ml of the given liquid (or 0.5 g of solid) in a
clean test tube and add about 0.1 g of finely powdered Ketone (R-CO-R) is
m-dinitrobenzene. Now add about 1 ml of dilute sodium No violet colour absent.
hydroxide solution and shake.
8. Test for amine group:
LITMUS TEST:
Place a drop of the given liquid (or pinch of the solid) on Amino (R-NH2)
the moist red litmus paper and note the change in No colour changes to group absent.
colour. blue
RESULT
The given organic compound contains Carboxylic acid (R-COOH) as a functional group.
Expt. 13 : To identify the functional group present in the given organic
compound - II
Experiment Observations Inference
1. Test for unsaturation:
ALKALINE KMnO4 TEST (BAEYER’S TEST):
Dissolve a little of the given organic compound in about 2
ml of water or acetone in a test tube. Add 1–2 drops of Pink colour of KMnO4 An unsaturation is
alkaline solution of KMnO4 (1%) and shake the mixture. gets decolourised. present.
2. Test for carboxylic group:
SODIUM HYDROGENCARBONATE TEST: No Brisk Carboxylic group
Added a pinch of NaHCO3 to 0.2 ml of organic effervescence. (R-COOH) is absent.
compound in a test tube.
3. Test for phenolic group:
FERRIC CHLORIDE TEST:
Added 0.2 ml of organic compound to 2–3 ml neutral No green or violet Phenolic (Ar-OH)
FeCl3 solution in a test tube. colour obtained. group is absent.
4. Test for alcoholic group:
CERIC AMMONIUM NITRATE TEST:
Place about 1 ml of the given compound in a clean dry No pink or red colour
Alcoholic (R-OH)
test-tube, add a few drops of ceric ammonium nitrate
group is absent.
reagent and shake well.
5. Test for carbonyl group:
2, 4-DINITROPHENYL HYDRAZINE TEST (2, 4—
DNP TEST) Orange-yellow ppt. Carbonyl group is
Take 0.5 ml or 0.5 g of the given compound in a clean formed. present
dry test-tube, add rectified spirit until the compound
just dissolves. Now add a few drops of 2, 4-
dinitrophenyl hydrazine solution. Cork the test-tube,
shake the mixture and allow it to stand for 5 minutes.
6. Test for aldehydic group :
FEHLING’S TEST:
No red precipitate Aldehyde (R-CHO) is
Take 1 ml each of Fehling’s solution A and B in a test absent.
tube. Add 4–5 drops (or 0.2 g) of the given organic
compound and warm the test tube in hot water bath for
4–5 minutes.
7. Test for Ketonic group :
m-DINITROBENZENE TEST: Violet colour Ketone (R-CO-R) is
Place 0.5 ml of the given liquid (or 0.5 g of solid) in a Present.
clean test tube and add about 0.1 g of finely powdered
m-dinitrobenzene. Now add about 1 ml of dilute sodium
hydroxide solution and shake.
8. Test for amine group:
Amino (R-NH2)
LITMUS TEST:
No colour changes to group absent.
Place a drop of the given liquid (or pinch of the solid) on blue
the moist red litmus paper and note the change in
colour.
RESULT
The given organic compound contains Ketone (R-CO-R) as a functional group.
Expt. 14 : To identify the functional group present in the given organic
compound - III
Experiment Observations Inference
1. Test for unsaturation:
ALKALINE KMnO4 TEST (BAEYER’S TEST):
Dissolve a little of the given organic compound in about 2
ml of water or acetone in a test tube. Add 1–2 drops of Pink colour of KMnO4 An unsaturation is
alkaline solution of KMnO4 (1%) and shake the mixture. does not gets absent.
decolourised.
2. Test for carboxylic group:
SODIUM HYDROGENCARBONATE TEST: Carboxylic group
Added a pinch of NaHCO3 to 0.2 ml of organic No Brisk effervescence. (R-COOH) is absent.
compound in a test tube.
3. Test for phenolic group:
FERRIC CHLORIDE TEST: No green or violet colour Phenolic (Ar-OH)
Added 0.2 ml of organic compound to 2–3 ml obtained. group is absent.
neutral FeCl3 solution in a test tube.
4. Test for alcoholic group:
CERIC AMMONIUM NITRATE TEST:
Alcoholic (R-OH)
Place about 1 ml of the given compound in a clean dry Pink or red colour
group is Present.
test-tube, add a few drops of ceric ammonium nitrate
reagent and shake well.
5. Test for carbonyl group:
2, 4-DINITROPHENYL HYDRAZINE TEST (2, 4—
DNP TEST)
Take 0.5 ml or 0.5 g of the given compound in a clean
dry test-tube, add rectified spirit until the compound No Orange-yellow ppt. Carbonyl group is
just dissolves. Now add a few drops of 2, 4- formed. absent
dinitrophenyl hydrazine solution. Cork the test-tube,
shake the mixture and allow it to stand for 5 minutes.
6. Test for aldehydic group :
FEHLING’S TEST:
Take 1 ml each of Fehling’s solution A and B in a test
tube. Add 4–5 drops (or 0.2 g) of the given organic No red precipitate Aldehyde (R-CHO) is
compound and warm the test tube in hot water bath for absent.
4–5 minutes.
7. Test for Ketonic group :
m-DINITROBENZENE TEST:
Place 0.5 ml of the given liquid (or 0.5 g of solid) in a
clean test tube and add about 0.1 g of finely powdered No violet colour Ketone (R-CO-R) is
m-dinitrobenzene. Now add about 1 ml of dilute sodium absent.
hydroxide solution and shake.
8. Test for amine group:
LITMUS TEST:
Place a drop of the given liquid (or pinch of the solid) Amino (R-NH2)
on the moist red litmus paper and note the change in No colour changes to group absent.
colour. blue
RESULT
The given organic compound contains Alcohol (R-OH) as a functional group.
Expt. 15 : To identify the functional group present in the given organic
compound - IV
Experiment Observations Inference
1. Test for unsaturation:
ALKALINE KMnO4 TEST (BAEYER’S TEST):
Dissolve a little of the given organic compound in about An unsaturation is
2 ml of water or acetone in a test tube. Add 1–2 drops of Pink colour of KMnO4 absent.
alkaline solution of KMnO4 (1%) and shake the mixture. does not gets Or not given by
decolourised. aromatic carbon-
carbon double bond.
2. Test for carboxylic group:
SODIUM HYDROGENCARBONATE TEST:
Added a pinch of NaHCO3 to 0.2 ml of organic Carboxylic group
compound in a test tube. No Brisk effervescence. (R-COOH) is absent.
3. Test for phenolic group:
FERRIC CHLORIDE TEST:
Added 0.2 ml of organic compound to 2–3 ml Green or violet colour Phenolic (Ar-OH) group
neutral FeCl3 solution in a test tube. obtained. is present.
4. Test for alcoholic group:
CERIC AMMONIUM NITRATE TEST:
Place about 1 ml of the given compound in a clean dry No pink or red colour
Alcoholic (R-OH) group
test-tube, add a few drops of ceric ammonium nitrate
is absent.
reagent and shake well.
5. Test for carbonyl group:
2, 4-DINITROPHENYL HYDRAZINE TEST (2,
4—DNP TEST)
Take 0.5 ml or 0.5 g of the given compound in a clean
No Orange-yellow ppt. Carbonyl group is
dry test-tube, add rectified spirit until the compound
formed. absent.
just dissolves. Now add a few drops of 2, 4-
dinitrophenyl hydrazine solution. Cork the test-tube,
shake the mixture and allow it to stand for 5 minutes.
6. Test for aldehydic group :
FEHLING’S TEST:
Take 1 ml each of Fehling’s solution A and B in a test No red precipitate Aldehyde (R-CHO) is
tube. Add 4–5 drops (or 0.2 g) of the given organic absent.
compound and warm the test tube in hot water bath
for 4–5 minutes.
7. Test for Ketonic group :
m-DINITROBENZENE TEST:
Place 0.5 ml of the given liquid (or 0.5 g of solid) in a No violet colour Ketone (R-CO-R) is
clean test tube and add about 0.1 g of finely powdered absent.
m-dinitrobenzene. Now add about 1 ml of dilute
sodium hydroxide solution and shake.
8. Test for amine group:
LITMUS TEST: Amino (R-NH2) group
Place a drop of the given liquid (or pinch of the solid) No colour changes to absent.
on the moist red litmus paper and note the change in blue
colour.
RESULT
The given organic compound contains Phenol (Ar-OH) as a functional group.
Expt. 16: To detect the presence of carbohydrates, fats and proteins in the
following food stuffs:
Grapes, potatoes, rice, butter, biscuits, milk, groundnut, besan(Gram Flour).
THEORY
The presence of carbohydrates, fats and protein in any food stuff is detected by performing the tests
for carbohydrates, fats and proteins with the extract of the food stuff. These tests do not interfere
with each other.
APPARATUS
Test tubes, beakers, glass rod, pestle mortar and burner.
PROCEDURE
First prepare the extract of the given food stuff by either dry grinding in the mortar with a pestle or
by boiling with minimum quantity of water extracting with a small quantity of an organic solvent after
grinding the food stuff. The extracts of some of the food stuffs can be prepared as given under:
For grapes — extract the juice
For potatotes — cut into slices and boil with water
For rice — boil with water
For butter — test directly
For biscuits — boil with water
For milk — test directly
For groundnut— grind in the mortar
OBSERVATIONS
Food Fehling's Iodine Test Biuret Solubility Spot Test
Item Test (Carbs) (Starch) Test Test (Fat)
(Protein (Fat)
)
Grapes Positive Positive Trace Insoluble
(Sugars (Some
present) protein)
Potatoes Positive Positive Positive Insoluble
(Starch (Strong
present) positive)
Rice Positive Positive Low Insoluble
(Starch (Strong positive
present) positive) (Less
protein
than
potatoe
s)
Butter Negative Negative Negativ Soluble Positive
e in (Transluce
chlorofor nt greasy
m spot)
Biscuits Positive Positive Positive Insoluble Positive
(Sugars and (Starch (Protein (Fat from (Transluce
starch from from flour) from butter/oil nt greasy
flour) flour) ) spot)
Food Fehling's Iodine Test Biuret Solubility Spot Test
Item Test (Carbs) (Starch) Test Test (Fat)
(Protein (Fat)
)
Milk Positive Weak Positive Insoluble Positive
(Lactose positive (Milk (Milk fat) (Transluce
sugar) (Less protein nt greasy
starch than casein) spot)
potatoes/ric
e)
Groundn Negative Negative Positive Soluble Positive
ut (High in (Transluce
protein) chlorofor nt greasy
m spot)
Besan Positive Positive Positive Insoluble Weak
(Gram (Carbohydrat (Starch (High (Trace positive
Flour) es from from protein fat) (Faint
chickpea chickpea from greasy
flour) flour) chickpe spot)
a flour)
Notes:
Fehling's test detects reducing sugars, not all carbohydrates.
Presence of starch is a type of carbohydrate.
Biuret test detects presence of proteins.
Solubility test in chloroform indicates presence of fats and oils.
Spot test is a confirmatory test for fats/oils.
RESULT
The given food stuff contains carbohydrates, fats and proteins.
