Post on 04-Apr-2018
transcript
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Aim:-
To defect the presence of adulterant (BRICK POWDER) IN Chilli Powder sample.
THEORY:-
Red chilli Powder is adulterated with either colours or brick powder. Brick powder
being heavier than chilli powder, settles at the bottom on dissolving it in a glass of
water. If colour has been added to chilli powder, then water becomes coloured.
APPARATUS:-
A Beaker.
A Glass Rod.
Chilli Powder Sample.
Water.
PROCEDURE:-
Add a pinch of chilli powder in a beaker containing water.
Stir the contents with glass rod.
Wait for some time.
Settling of brick powder at bottom and appearance of red color on the surface of
water indicates adulteration in the sample.
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AIM:-
To find out whether given sample or turmeric powder is pure or not.
THEORY:-
Yellow chalk powder, a common adulterant of turmeric powder gives
effervescence with dilute hydrochloric acid.
APPARTUS:-
Test tubes.
Test tube stand.
Dilute Hydrochloric acid.
Water.
PROCEDURE:-
Take about 0.5 g of the powdered sample in a test tube. Add to it about 1 ml of
dilute hydrochloric acid. Effervescence indicates the presence of chalk powder in
the sample.
Dilute the contents of the test tube with 25-30 ml of water. Disappearance of the
violet colour formed previously indicates the purity of turmeric powder. But if
violet color first formed with dil. HCl persists, then it is contaminated with yellow
dye.
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AIM:-
To test the presence of adulterant in given sample of sugar
THEORY:-
Any undissolved substance is left behind on dissolving sugar in it, then it is
indication of adulteration in it. Washing soda and chalk powder, both give
effervescence with dilute HCl. Hence, their presence in the sugar sample can be
detected by treating small amont of sugar with dilute HCl.
APPARATUS:-
Test tubes.
Test tube stand.
Dilute hydrochloric acid.
Distilled water.
PROCEDURE:-
Take about 1 g of the sugar sample in a test tube and add about 5 ml water to it.
Shake the contents of the tube for about 4-5 minutes. Presence of undissolved
substance indicates adulteration in the sugar.
Take about 1 g of sugar sample in a clean and dry test tube. Add to it about 2 ml of
dilute HCl. Effervescence on addition of acid indicates the presence of chalk or
washing powder in the sugar.
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AIM:-
To test the presence of adulterant in the given sample of Asafoetida and Tea
leaves.
APPRATUS:-
Test tubes.
Test tube stand.
Sample of Asafoetida and Tea Leaves.
Small amount of water and filter paper.
Bunsen burner.
PROCEDURE:-
Take a small amount of asafoetida in a test tube. To it, add a small amount of water.
Shake the contents well.
The formation of milky solution shows the absence of adulterant. If there are any
insoluble mass left behind, it shows presence of some adulterant in the given
sample.
Burn a small amount of asafoetida in a test tube. If it burns it is free from
adulterant. If it doesnt then there is some adulterant present in the sample.
Put some tea sample on a wet filter paper. If the filter paper colour changes
immediately, it confirms that the tea leaves have ben coloured.
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AIM:-
To test the presence of adulterants in the given sample of milk.
THEORY:-
Milk is an opaque white liquid secreted by female mammals like cows, buffaloes and
other animals. The main constituents of milk are carbohydrates, fats., vitamins and
proteins. The protein present in the milk is known as casein. Besides these, milk also
contains elements like K, Na, Ca, Mg, Fe, Cu, P, S and Cl2 in small amounts.
Unadulterated milk contains 4.5% fat in case of cows milk and 6% fat in case of
buffalo milk.
Addition of water to milk dilutes its fats contents and, therefore, lowers its
specific density. So presence of water in milk may be detected by measuring its
specific density. Specific density of pure milk is always greater than 1.026.
Presence of starch material in milk can be detected by exploiting the formation of
blue colored complex with iodine or tincture of iodine.
APPARATUS:-
Test tubes.
Lactometer.
Measuring cylinder.
Given sample of milk.
Sulphuric acid.
Iodine or tincture of iodine.
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OBJETIVE:-
Determination of fat percentage in milk.
THEORY:-
The method commonly used for the routine estimation of fat in milk, is known as
GERBER method. This gives accurate results when operated carefully.
PROCEDURE:-
Run from a burette 10 cm3 of 90% H2SO4 into a standard butyrometer, add slowly
11 cm3 of the sample to it with the help of a milk pipette. Also add 1cm 3 of pure
amyl alcohol. Stopper the butyrometer firmly and thoroughly mix the contents by
repeated inversion of the butyrometer until we get a uniform solution. When
uniform solution is not obtained, put the butyrometer in a steam bath for 10-15
minutes until all casein goes into the solution.
Centrifuge the tube. Adjust the fat layer with the aid of rubber stopper and read
fat % directly from scale.
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OBJECTIVE:-
Determination of Specific Gravity of the milk sample.
THEORY & APPARATUS:-
The apparatus used is known as Lactometer. The stem of the lactometer is
graduated downwards as W, 1, 2, 3 and M. W and M mean pure water and pure milk
while the parts 1, 2, 3 represent the portion of milk and water. The mark 1 indicates
1 part milk and 3 parts water. This test of milk is not very conclusive. The skimmed
milk shows a higher specific gravity than even pure milk as cream which is lighter
substance has been separated. Thus skimmed milk to which some water has been
added will be indicated as pure milk by the lactometer. To find the purity of milk,
the fat percentage is calculated. This is done with the help of a butyrometer.
Non fatty solid may be calculated by using the given formula:
+ 0.2 + 0.14 = ...
Where F is fat percentage.
PROCEDURE:-
Take a jar and fill it with milk sample.
Now take a clean lactometer and it in milk sample.
Read the scale. The scale reading will directly give the specific gravity of milk.
RESULT:-the specific gravity of milk is 2.3
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OBJECTIVE:-
To test the presence of cane sugar in given sample of milk
PROCEDURE:-
Take 5 cm3 of given milk sample in a test tube. To it add 0.05 g resorcin and 0.5 cm3
concentrated HCl. Formation of rose red colour shows the presence of sugar.
OBJECTIVE:-
To test the presence of Lactose in a given sample of milk.
PROCEDURE:-
Milk contains a carbohydrate known as LACTOSE.
Take 1 cm3 of the milk sample in the test tube. To it, add 2% alcoholic solution of
-naphthol.
Now slowly add concentrated H2SO4 from the side of the test tube.
Formation of pink colour at the bottom of the test tube indicates the presence of
carbohydrate in the given sample of milk.
This test is also known as Molischs Test and 2% alcoholic solution of -naphathol is
known as Molischs Reagent.
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OBJECTIVE:-
To test the presence of Protein in the given sample of milk.
PROCEDURE:-
Take about 1 cm3 of the milk sample in a test tube.
To it add alkaline solution of copper sulphate.
Formation of violet colour shows the presence of protein in the given sample of
milk.
This test is known as Biuret Test.
Take about 1 cm3 of the milk sample in a test tube.
To it, add about 1 cm3 of mercuric nitrate solution.
Boil the solution.
Formation of red colour shows the presence of protein in the given sample of milk.
This test is known as Millons Test.
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OBLECTIVE:-
To test the presence of water in the given sample of milk.
PROCEDURE:-
Put few drops of milk sample on a smooth and oily surface. If the milk is pure then
its drops will be stable for some time and will leave a white streak.
Measure the specific density of the milk with a lactometer.
Babcock test for purity of milk: This determines the fat content in milk. About
20 ml of milk is taken with the help of a pipette in a small narrow necked graduated
flask and add H2SO4 with it. The flask is shaken until the mixture becomes dark
coloured. The acid doesnt affect the fat but it dissolves other solids in the milk.
The flask is then centrifuged by which the fat is forced towards the neck, being
lighter than other contents. Sufficient warm water is added to bring the fat in the
narrow neck, where its exact percentage is read on the graduation mark.
Testing the presence of starch in milk: Take 5 ml of milk sample in a test tube.
Heat it to almost boiling. Cool and few drops of iodine solution and shake the
contents. Appearance of blue colour indicates presence of starch in milk. If it is
pure, then there will be deep yellow coloration due to casein, a protein of milk.
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AIM:-
To test the presence of vanaspati ghee and starchy matter in given sample of pure
ghee.
THEORY:-
Starchy matter can be detected with iodine. Iodine form blue coloured complex
with starch. Vanaspati ghee gives pink colour with furfural.
APPRATUS:-
Test tube.
Test tube stand.
Test tube holder.
Iodine or tincture of iodine.
Hydrochloric acid.
Sugar.
Given sample of ghee.
PROCEDURE:-
Detection of starchy matter: Take about 0.5 g of the given ghee in the test tube.
Add about 1 ml of water to it and boil. Cool and add a drop of iodine or tincture of
iodine solution. Appearance of blue colour indicates presence of starchy matter in
the sample.
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Detection of vanaspati: Take about 0.5 g of given sample of ghee in a test tube.
Heat the tube gently so that the ghee melts and add a little sugar and Hydrochloric
acid to it. Shake the contents of five minutes. Presence of pink colour in the
aqueous layer is indication of vanaspati ghee in the sample.
AIM:-
To test the purity of given sample of oil or fat.
THEORY:-
Oils and fats are mostly adulterated with:
Dyes to improve the colour of material.
Paraffin wax or hydrocarbons to increase the rate of products ( vegetable ghee),
thereby increasing the profit
Cheap varieties of similar materials, example mustard oil is adulterated with
agremone oil.
The presence of these in oils or fats can be detected by exploiting their
characteristics property.
APPARATUS:-
Test tubes
Test tube stand
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Hydrochloric acid
Nitric acid
Light petroleum
Sulphuric acid
Glacial acetic acid
Acetic anhydride
Procedure:-
DETECTION OF DYES IN OILS AND FATS:-
Take 2 g of fat in a a test tube. Add 5 ml of light petroleum to avoid its
solidification and 1 ml of hydrochloric acid to it. Shake the tube thoroughly and
allow to stand for some time. Appearance of pink color in the layer will lower layer
will indicate the presence of dyes.
Mix 1 ml (1 g) of the fat will 1 ml of mixture of concentrated sulphuric acid and
glacial acetic acid in 1:4 ratio and heat the mixture nearly to boiling. Pink or reddish
color of the solution indicates the presence of dyes.
DETECTION OF PARAFFIN WAX AND HYDROCARBONS:-
Heat small amount of unsaponifiable matter of oils with acetic anhydride carefully.
If small droplets of oil will be found floating on the surface of unused acetic
anhydride, then the oil is surely adulterated with paraffin wax or hydrocarbon.
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DETECTION OF ARGEMONE OIL:-
Take about 5 ml of oil in a test tube. Add few drops of conc. Nitric acid into it and
shake carefully. Orange or red colour indicates the presence of agremone oil
DEDECTION OF MINERAL OIL:-
Take about 2 ml of them oil in test tube. Add into it about of N/2 nitric acid. Now,
heat the test tube over water bath. Turbidity in the contents of the test tube
indicate presence of mineral oils in given samples.