To study fat in pure form and to detect into presence in given food sample

Aim: To study fat in pure form and to detect into presence in given food sample 

Material required: Test-tube, test-tube stand, test tube holder, burner etc.

Theory: Fats and oil are esters of long chain fatty acids and glycerol and thus also called glycerides. Fats contains saturated fatty acids while oil contain unsaturated fatty acids.

 Observation Table-

S.N.	EXPERIMENT	OBSERVATION	INFERENCE
1.	Spot test: put a small amount of sample on a filter paper and press with another filter paper	Translucent spot appears on filter paper	Fat is present
2.	Acrolein test: Take a few drops of sample in a test tube. Add few drops of potassium bisulphite to it and Heat.	Irritating smell appears due to the form of acrolein vapours.	Fat is present
3.	Solubility test: Take a small amount of sample in 3 test tubes. Add water, alcohol, and chloroform in 1, 2, 3 test tube respectively.	Sample does not dissolve in H2O but is soluble in alcohol on heating and soluble in chloroform.	Fat is present

 

Result: Fat is present in given sample of food.

To study carbohydrates in pure form of detect its presence in food

Aim: To study carbohydrates in pure form of detect its presence in food. 

Material required: Test-tube, test-tube stand, test tube holder, burner etc.

Theory: Carbohydrates are Polyhydroxy aldehydes or polyhydroxy ketones, their derivatives and the substance which yield them on hydrolysis carbohydrates are classified as sugars and non-sugars. Sugars like glucose, fructose and cane sugar are crystalline.

Among sugars, glucose, fructose, and lactose are reducing while sucrose is non reducing sugar.

 

S.N.	EXPERIMENT	OBSERVATION	INFERENCE
1.	Conc. H2SO4 test: Sample + Conc. H2SO4 + Heat	Charring with burnt sugar smell.	Carbohydrates present.
2.	Fehling solution test: Sample solution + 1 ml of Fehling A + 1 ml of Fehling B + D	Red ppt	Reducing sugar is present
3.	Tollen’s reagent: Aq. Solution of sample + 2 ml of Tollens reagent + D	Silver mirror is formed along the surface of test tube.	Reducing sugar is present
4.	Benedict’s Solution test: Aq solution of sample + Benedict’s reagent + Heat	Red ppt	Reducing sugar is present
5.	Iodine test: Sample Solution + few drops of iodine solution	Violet colour	Starch is present

 

Result : Carbohydrates is present in given sample of food.

To identify the functional group in the given organic compound

Aim : To identify the functional group in the given organic compound.

Material Required: Test-tube, test-tube stand, test tube holder, dropper, litmus solution, 2,4 DNP, dil. HCl, NaOH, sodium, nitroprusside, meta dinitro benzene.

Physical Properties:

State: liquid 

Color: colourless

Odor: Nail paint remover like smell 

Water solubility: soluble in water

Flammability: Burn with non-sooty flame (Aliphatic) 

Preliminary test :

S.N.	Experiment	Observation	Inference
1.	Litmus test: Organic compound + 2 drops of litmus solution.	No change	-COOH or phenolic   may present
2.	Organic compound + dil. HCl + NaOH	No ppt or oily layer	-NH2 group is absent.
3.	Organic compound + 2 ml of 2,4-DNP shake it and allow to stand	Orange-red ppt	Carbonyl group is present Aldehyde or ketonic group may be present

Confirmatory test :

S.N.	Experiment	Observation	Inference
1.	Organic compound + sodium nitroprusside + 2 – 3 drops of NaOH and shake.	Red color or wine- red color	>C=O group present
2.	Organic compound + Meta dinitrobenzene + NaOH	Violet  color which fades  on standing.	>C=O group present

 

Result: Given organic compound contains Ketonic grp. (>C=O)

To identify the functional group in the given organic compound

Aim : To identify the functional group in the given organic compound.

Material Required : Test tube, test tube stand, test tube holder, dropper, litmus solution, 2,4 DNP, dil HCl, NaOH, reagent, Fehling solution, Schiff reagent.

Physical Properties:

State: liquid 

Color: colourless 

Odor: Pungent

Water solubility: soluble in water

Flammability: Burn with non-sooty flame (Aliphatic) 

Preliminary test :

S.N.	Experiment	Observation	Inference
1.	Litmus test: Organic compound + 2 drops of litmus solution.	No change	-COOH or phenolic (–OH) is present
2.	Organic compound + dil. HCl + NaOH	No ppt or oily layer	-NH2 group is absent.
3.	Organic compound + 2 ml of 2,4-DNP shake it and allow to stand	Orange-red ppt	Carbonyl group is present Aldehyde or ketonic group may be present

Confirmatory test :

S.N.	Experiment	Observation	Inference
1.	Schiff's solution test: Organic compound + 2 ml of Schiff's reagent.	Pink color Obtained	-CHO group present
2.	Fehling’s solution test: Organic compound + Fehling’s solution (A + B) + boil in a water bath	Red ppt.	-CHO group present

 

Result: Given organic compound contains aldehydic grp. (- CHO)

To identify the functional group in the given organic compound

Aim : To identify the functional group in the given organic compound.

Material Required : Test tube, test tube stand, test tube holder, dropper, litmus (blue), NaHCO3, conc. H2SO4 , NH4OH, FeCl3

Physical Properties:

State: Solid 

Color: White 

Odor: phenolic

Water solubility: insoluble

Flammability: Burn with non-sooty flame (Aliphatic) 

Preliminary test :

S.N.	Experiment	Observation	Inference
1.	Litmus test: Organic compound + 2 drops of litmus solution.	Litmus solution turns from blue to red.	-COOH or phenolic (–OH) may be present
2.	Organic compound + NaHCO3 solution.	No effervescence.	-COOH group absent Phenolic (–OH) may be present.

Confirmatory test :

S.N.	Experiment	Observation	Inference
1.	FeCl3 Test: Organic compound + dil. FeCl3 solution	Green blue or violet coloration	Phenolic group is confirmed
2.	Phthalic test: Organic compound + phthalic acid + 2-3 drops H2SO4 + D then cool and add dil. NaOH	blue or red coloration	Phenolic group is confirmed

 

Result: The given organic comp. contains phenolic group.

           

To identify the functional group in the given organic compound

Aim : To identify the functional group in the given organic compound.  

Material Required : Test tube, test tube stand, test tube holder, dropper litmus (blue) solution, dil. HCl, NaOH, Na metal, dil. H2SO4, CH3COOH.

Physical Properties:

State: Liquid 

Color: Colourless

Odor: Spirit like smell 

Water solubility: soluble

Flammability: Burn with non-sooty flame (Aliphatic) 

Preliminary test :

S.N.	Experiment	Observation	Inference
1.	Litmus test: Organic compound + 2 drops of litmus solution.	No change	-COOH or – OH is absent
2.	Organic compound + dil. HCl + NaOH	No ppt or oily layer	-NH2 group is absent.
3.	Organic compound + Na metal	H2 gas evolves	-OH(alcohol) group     may be present

Confirmatory test :

S.N.	Experiment	Observation	Inference
1.	Cerric ammonium nitrate Test : Organic compound + cerric ammonium nitrate	Red color appears	-OH group is confirmed
2.	Ester Test : Organic compound + CH3COOH + Conc. H2SO4 (1 – 2 drops) + Heat.	Fruity smell of ester.	-OH group is confirmed

Result : The functional group present in the given organic compound is alcoholic group (- OH)