Showing posts with label Identification tests. Show all posts
Showing posts with label Identification tests. Show all posts

Wednesday, April 27, 2022

Identification test for zinc oxide

Learn the identification test for zinc oxide through a laboratory experiment or practical.

Aim:

To perform identification test for zinc oxide.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, funnel, dropper, rubber stopper, test tube stand, test tube holder, filter paper, balance, etc.

Chemicals:
Zinc oxide (ZnO), sodium sulphide (Na2S), sodium hydroxide (NaOH), ammonium chloride (NH4Cl), ammonium mercuric thiocyanate (C4H8HgN6S4), cupric sulphate (CuSO4), barium chloride (BaCl2), potassium ferrocyanide (C6FeK4N6), lead acetate (Pb(C2H3O2)2), sulphuric acid (H2SO4), hydrochloric acid (HCl), etc.

Theory:

Identification tests are used to determine the drug's quality so that it can be used safely. This identification of ZnSO4 is usually based on the reactions of ions and cations present in the sample, by which we can determine the quality of the drug.

Zinc oxide has the formula ZnO and is an inorganic substance. It comes as a white amorphous powder that is water-insoluble but soluble in dilute acids and bases. Zinc oxide is used as an ingredient in pharmaceutical ointments to treat skin irritations.

Procedure:

Identification tests for zinc ion:

  1. When heated to a high temperature, the sample turns yellow; However, the yellow color fades as the sample cools.
  2. Take 0.3 gm of zinc oxide and dissolve it in 4.5 ml of 2M HCl, then make up the volume to 15 ml with distilled water. The prepared solution gives the characteristic reaction of zinc salt as follows:
  •  Take 05 ml of the above-prepared solution and add 0.2 ml of NaOH solution, by which a white precipitate is produced.
  • Take 05 ml of the above-prepared solution and acidify it with a dilute solution of sulphuric acid. Add a drop of cupric sulfate solution (0.1% w/v) and 02.00 ml of ammonium mercuric thiocyanate solution by which a violet precipitate is formed.
  •  Take 05 ml of the above-prepared solution and add 02.00 ml of potassium ferrocyanide solution. This forms a white precipitate that is insoluble in dilute hydrochloric acid.


Result:

The given sample is identified as zinc sulphate.
Posted by No comments:
Labels:

Identification test for zinc sulphate

Learn the identification test for zinc sulfate through a laboratory experiment or practical.

Aim:

To perform identification test for zinc sulphate.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, funnel, dropper, rubber stopper, test tube stand, test tube holder, filter paper, balance, etc.

Chemicals:
Zinc sulphate (ZnSO4), sodium sulphide (Na2S), sodium hydroxide (NaOH), ammonium chloride (NH4Cl), ammonium mercuric thiocyanate (C4H8HgN6S4), cupric sulphate (CuSO4), barium chloride (BaCl2), potassium ferrocyanide (C6FeK4N6), lead acetate (Pb(C2H3O2)2), sulphuric acid (H2SO4), hydrochloric acid (HCl), etc.

Theory:

Identification tests are used to determine the drug's quality so that it can be used safely. This identification of ZnSO4 is usually based on the reactions of ions and cations present in the sample, by which we can determine the quality of the drug.

Zinc sulfate is an inorganic compound that comes as colorless, odorless, transparent crystals or white crystalline powder. Zinc sulphate is soluble in water and insoluble in ethanol. It is an efflorescent substance used as an astringent.

Procedure:

Identification tests for zinc ion:

  1. Take 0.1 gm of sample and dissolved in 05.00 ml of distilled water, then add 0.2 ml of NaOH solution by which white precipitate is produced.
  2. Take 0.1 gm of sample and dissolved in 05.00 ml of distilled water, acidify it with a dilute solution of sulphuric acid. Add a drop of cupric sulfate solution (0.1% w/v) and 02.00 ml of ammonium mercuric thiocyanate solution by which violet precipitate is formed.
  3. Take 0.1 gm of sample and dissolved in 05.00 ml of distilled water, add 02.00 ml of potassium ferrocyanide solution forms a white precipitate that is insoluble in dilute hydrochloric acid.

Identification tests for sulphate ion:

  1. Take 01.00 ml of barium chloride solution and add it to the sample solution. A white precipitate is formed due to the formation of ZnSO4.
  2. Take 01.00 ml of lead acetate solution and add it to the sample solution. A white precipitate is formed due to the formation of lead sulphate.

Result:

The given sample is identified as zinc sulphate.
Posted by No comments:
Labels:

Monday, April 25, 2022

Identification test for sodium thiosulphate

Learn the identification test for sodium thiosulphate through a laboratory experiment or practical.


Aim:

To perform identification test for sodium thiosulphate.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, funnel, dropper, rubber stopper, test tube stand, test tube holder, filter paper, balance, etc.

Chemicals:
Sodium thiosulphate (Na2S2O3), ferric chloride (FeCl3), iodine (I2), bromine solution (Br), hydrochloric acid (HCl), etc.

Theory:

This identification of Na2S2O3 is usually based on the reactions of ions and cations present in the sample, by which we can determine the quality of the drug. It comes in the form of crystalline powder which is odorless and colorless that dissolves well in water. It is mostly used in different industries, also used in analytical chemistry, gold mining, the pharmaceutics sector, and as an antidote to cyanide poisoning.

Procedure:

To perform the following tests, prepare a sample solution by dissolving 01.00 g in 20.00 ml of distilled water.

Identification tests for sodium-ion:

  1. Take 02 ml of prepared sample solution and 2 ml (15% w/v) of potassium carbonate solution, and heat it to boiling. No precipitate is formed, and then adds 04 ml of freshly antimonite solution and heated to a boil. Then cool in an ice bath and rub the inside wall of the test tube with a glass rod. A dense white precipitate of sodium antimonite is formed.
  2. Using acetic acid, acidify 01 ml of the above solution, and add additional magnesium uranyl acetate solution. The yellow crystalline precipitate of sodium magnesium uranyl acetate is formed.

Identification tests for thiosulphate ion:

  1. Take 0.1 g of the sample in 5 ml of water and add 02 ml of HCl. A white precipitate is formed, which quickly turns yellow because of the dissociation of sulfur, and sulfur dioxide is produced, which is identified by its odor.
  2. Take 0.1 g of the sample in 5 and add 02 ml of ferric chloride test solution, which produces a deep purple color that fades quickly. 
  3. Add a few drops of iodine solution to a 10% w/v sample solution. The color has discharged. It happens because of an oxidation-reduction reaction.

Result:

The given sample is identified as sodium thiosulphate.
Posted by No comments:
Labels:

Identification test for sodium chloride

Learn the identification test for sodium chloride through a laboratory experiment or practical.

Aim:

To perform identification test for sodium chloride.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, funnel, dropper, rubber stopper, test tube stand, test tube holder, filter paper, balance, etc.

Chemicals:
Sodium chloride (), potassium carbonate (K2CO3), silver nitrate (AgNO3), potassium dichromate (K2Cr2O7), magnesium uranyl acetate (MGUO2), diphenylcarbazide (C13H14N4O), ammonia (NH3), sulphuric acid (H2SO4), sodium antimonite (NaSb(OH)6), acetic acid (CH3COOH), nitric acid (HNO3), etc.

Theory:

This identification of NaCl is usually based on the reactions of ions and cations present in the sample, by which we can determine the quality of the drug. Sodium chloride is also known as a salt, an ionic compound, with the chemical formula NaCl.

It comes in colorless cubic crystals or white crystalline powder, which is odorless and has a saline taste. It is used as an electrolyte replenishment and pharmaceutical aid. It is soluble in water, methanol, ammonia, and glycerin; and slightly soluble in ethanol.

Procedure:

To perform the following tests, prepare a sample solution by dissolving 01.00 g in 20.00 ml of distilled.

Identification tests for sodium ions:

  1. Take 02 ml of prepared sample solution and 2 ml (15% w/v) of potassium carbonate solution, and heat it to boiling. No precipitate is formed, then add 04 mL of freshly antimonite solution and heat to a boil. Then cool in an ice bath and, if required, rub the inside wall of the test tube with a glass rod. A dense white precipitate of NaSb (OH) 6 is formed.
  2. Using acetic acid, acidify 1 ml of the above solution, and add additional magnesium uranyl acetate solution. The yellow crystalline precipitate of sodium magnesium uranyl acetate is formed.

Identification tests for chloride ion:

  1. Take 01 ml of dilute nitric acid and add it to 03 ml of prepared chloride solution. Then add 2-4 drops of silver nitrate solution. A white precipitate of AgNO3 is formed. When dilute ammonia is added, the precipitate dissolves to form a complex.
  2. Add 0.2 g potassium dichromate and 01 ml H2SO4 to a small amount of sodium chloride in a test tube. Over the mouth of the test tube, place a filter-paper strip moistened with 0.1 ml diphenylcarbazide solution. The paper turns violet-red.

Result:

The given sample is identified as sodium chloride.
Posted by No comments:
Labels:

Saturday, April 23, 2022

Identification test for magnesium sulphate

Learn the identification test for magnesium sulfate through a laboratory experiment or practical.

Aim:

To perform identification test for magnesium sulphate.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, funnel, dropper, rubber stopper, test tube stand, test tube holder, filter paper, balance, etc.

Chemicals:
Magnesium sulphate (MgSO4), disodium hydrogen phosphate (Na2HPO4), sodium hydroxide (NaOH), ammonium chloride (NH4Cl), lead acetate (Pb(C2H3O2)2), barium chloride (BaCl2), ammonia solution, and titan yellow (C28H19N5Na2O6S4), etc.

Theory:

This identification of MgSO4 is usually based on the reactions of ions and cations present in the sample, by which we can determine the quality of the drug. Magnesium sulphate, also known as Epsom salt, is a salt with the formula MgSO4.7H2O that contains magnesium cations Mg2+ and sulphate anions SO2-4. It is a white crystalline solid, odorless, colorless crystal that is soluble in water and slightly soluble in ethanol in ethanol.

It works as an anticonvulsant, a calcium channel blocker, a cardiovascular drug, an anesthetic, a tocolytic agent, an anti-arrhythmia drug, an analgesic, and a fertilizer, among other things.

Procedure:

Prepare a sample solution by dissolving 01 g in 20 ml of distilled water and performing the tests listed below.

Identification tests for magnesium ion:

  1. Take 02.00 ml of the prepared sample and add 01.00 ml of dilute ammonia solution. A white magnesium hydroxide precipitate is formed, which dissolves when 01.00 ml of 02 M ammonium chloride solution is added.
  2. Add 01.00 ml of 0.25 M disodium hydrogen phosphate solution to 01.00 ml of the above solution. Magnesium ammonium phosphate appears as a white precipitate.
  3. Add 0.2 ml of a 0.1 percent w/w titan yellow solution and 0.5 ml of 0.1 M NaOH to 0.5 ml of a neutral/slightly acidic solution of magnesium sulphate. A bright red turbidity forms, which settles into a bright red precipitate over time.

Identification tests for sulphate ion:

  • To the prepared sample solution, add 01.00 ml of barium chloride solution. Due to the formation of MgSO4, a white precipitate is formed.
  • To 01.00 ml of the above solution, add 01.00 ml of lead acetate solution. Because the formation of lead sulphate causes a white precipitate to be formed.

Result:

The given sample is identified as magnesium sulphate.
Posted by No comments:
Labels:

Identification test for iodine

Learn the identification test for iodine through a laboratory experiment or practical.

Aim:

To perform an identification test for iodine.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, funnel, dropper, rubber stopper, test tube stand, test tube holder, balance, etc.

Chemicals:
Iodine (I2), potassium iodide (KI), starch mucilage, etc.

Theory:

Identification tests are used to determine the drug's quality so that it can be used safely. The chemical element iodine has the symbol I and the atomic number 53. Iodine is the fourth halogen in the periodic table, belonging to group 17 below fluorine, chlorine, and bromine; it is the heaviest and most stable member of its group. It is freely soluble in chloroform, ether, and carbon disulfide, soluble in ethanol, and slightly soluble in water.

Procedure of identification tests for iodine:

  • When iodine is slowly heated, violet vapors are produced, which condense to form a blue-black crystalline sublimation.
  • In a solution of potassium iodide, dissolve 2-4 drops of iodine crystals and add a few drops of starch mucilage. When you boil it, it turns a deep blue color that fades away but reappears when you cool it.

Result:

The given sample is identified as iodine.
Posted by No comments:
Labels:

Thursday, April 21, 2022

Identification test for hydrogen peroxide

Learn the identification test for hydrogen peroxide through a laboratory experiment or practical.

Aim:

To perform identification test for hydrogen peroxide.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, funnel, dropper, rubber stopper, test tube stand, test tube holder, balance, etc.

Chemicals:
Hydrogen peroxide (H2O2), sodium hydroxide (NaOH), potassium chromate (K2CrO4), sulphuric acid (H2SO4), ether ((C2H5)2O), etc.

Theory:

Identification tests are used to determine the drug's quality so that it can be used safely. Hydrogen peroxide is a reactive oxygen species with an oxygen–oxygen single bond. It is a colorless, odorless liquid having a bitter taste. It's a very pale blue liquid that's slightly more viscous than water in its purest state.

Hydrogen peroxide is an antiseptic and topical anti-infective agent used as an oxidizer, and bleaching agent. It is unstable, readily decomposing to oxygen and water with the release of heat.

Procedure of identification tests for hydrogen peroxide:

  • Add 01.00 ml dilute solution of NaOH to hydrogen peroxide and heat it. Because of decomposition, oxygen is evolved:
2H20 → 2H2O + O2
  • Acidify the hydrogen peroxide solution by adding 02.00 ml of a dilute solution of sulfuric acid. Add a drop solution of potassium chromate and 02.00 ml of ether. The formation of chromium pentoxide causes the ethereal layer to turn blue.
KC2rO4 + H2SO4 + 2H202 → CrO5 + K2SO4 + 3H2O

Result: 

The given sample is identified as hydrogen peroxide.
Posted by No comments:
Labels:

Identification test for bentonite

Learn the identification test for bentonite through a laboratory experiment or practical.

Aim:

To perform identification test for bentonite.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, funnel, dropper, rubber stopper, test tube stand, test tube holder, balance, etc.

Chemicals:
Bentonite, anhydrous sodium carbonate (Na₂CO₃), ammonium chloride (NH4Cl), sodium hydroxide (NaOH, hydrochloric acid (HCl), thioacetamide (C2H5NS), quinalizarin (C14H8O6), etc.

Theory:

Identification tests are used to determine the drug's quality so that it can be used safely. This identification of bentonite is usually based on the reactions of ions and cations present in the sample, by which we can determine the quality of the drug. Bentonite is a suspension agent made up of colloidal hydrated aluminum silicate.

Bentonite is an odorless powder that's pale buff or cream in color and has a slightly earthy taste. It is water-insoluble, however, when water is added, it expands to around twelve times its original volume. It is insoluble in organic solvents and does not swell upon contact with them.

Procedure:

Fuse 02.00 gm of anhydrous sodium carbonate and 01.00 gm of the sample, then warm the residue with 10.00 ml distilled water. Filter the residue, wash it with 05.00 ml of water, and combine the filtrate and washings. Do the test for the presence of aluminum in the residue and silica in the filtration.

Identification tests for barium ion:

  • Perform the following tests by dissolving the residue in 10.00 ml of weak hydrochloric acid. Add 0.5 ml of thiocetamide reagent to 02.00 ml of the above-prepared solution. No precipitate is formed. Add 2N solution of sodium hydroxide in a dropwise manner. A gelatinous white precipitate of aluminum hydroxide (Al(OH)3) is found.
Identification test for bentonite
  • In the 02.00 ml of the above solution add 2-4 drops of freshly made 0.05 percent w/v quinlizarin in a 1 percent w/v NaOH solution. Boil, cool, then acidify with an excess of acetic acid, you get a reddish violet color.

Identification test for silica:

  • Add 03.00 ml of dilute HCl to the filtrate obtained after filtration and washings. A gelatinous precipitate of metasilicic acid is formed.

Result:

The given sample is identified as bentonite.


You may also like this
Posted by No comments:
Labels:

Identification test for borax

Learn the identification test for borax through a laboratory experiment or practical.

Aim:

To perform identification test for borax.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, porcelain dish, dropper, rubber stopper, test tube stand, test tube holder, turmeric paper, balance, etc.

Chemicals:
Borax (Na₂[B₄O₅(OH)₄]•8H₂O), sodium hydroxide (NaOH), hydrochloric acid (HCl), sulphuric acid (H2SO4), ammonia solution, etc.

Theory of identification test for borax:

Identification tests are used to determine the drug's quality so that it can be used safely. Borax, commonly known as sodium tetraborate, sodium borate, or disodium tetraborate, is a transparent, colorless crystal. 

It's commonly used as a household cleaner and a laundry detergent booster. It is a bacteriostatic and pharmaceutical aid. It is an odorless, alkaline chemical with a salty taste. Borax is soluble in boiling water, slightly soluble in water, and insoluble in alcohol.

Procedure of identification tests for borax:

  • Acidify 5% borax solution with HCl, then moisten a piece of turmeric paper with it, and dry. The paper turns pink or brownish-red in color. On the paper, put a dilute ammonia solution or a sodium hydroxide solution. The paper turns a blue or greenish-black color.
  • In a porcelain dish, ignite a mixture of borax, sulfuric acid, and alcohol by which a greenish-tinged flame is produced.

Observation table:

Sr.

Identification test

Observation

Inference

1

5% of sample solution+ HCl → Using this solution, moisten a piece of turmeric paper.

Paper turns pink or brownish red

Borax:

Present/Absent

2

In a porcelain dish, ignite a mixture

Greenish flame

Borax:

Present/Absent

Result:

The given sample is identified as borax.


Posted by No comments:
Labels:

Wednesday, April 20, 2022

Identification test for boric acid

Learn the identification test for boric acid through a laboratory experiment or practical.

Aim:

To perform an identification test for boric acid.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, dropper, rubber stopper, test tube stand, test tube holder, balance, etc.

Chemicals:
Boric acid (H3BO3), methanol (CH3OH), sulphuric acid (H2SO4), etc.

Theory of identification test for boric acid:

Identification tests are used to determine the drug's quality so that it can be used safely. Boric acid is often used as an antiseptic, insecticide, flame retardant, neutron absorber, or chemical precursor to other chemical compounds. It is also used as a dusting powder. 

It's a crystalline powder that's colorless or white, odorless, and has some bitter taste. It is sparingly soluble in water and ethanol, and freely soluble in boiling water, ethanol, and glycerin.

Procedure of identification tests for boric acid:

  1. With gentle warming, dissolve 0.1 gm of boric acid in 05 ml of methyl alcohol containing a few drops of H2SO4. Perform the flame test by igniting the solution. The flame has a green border because of the formation of methyl bromate.
  2. Taker 03 gm of boric acid and dissolve it in 90 ml of boiling water and cool. The solution is faintly acidic.
Identification test for boric acid

Observation table:

Sr.

Identification test

Observation

Inference

1

Dissolve 0.1 gm by warming+05 ml methanol+4-5 drops of H2SO4.

Flame test: Ignite the solution

Green flame

Boric acid:

Present/Absent

2

03 gm of sample+90 ml of water (boiling) and cool

Acid solution

Boric acid:

Present/Absent

Result:

The given sample is identified as boric acid.
Posted by No comments:
Labels:

Identification test for barium sulphate

Learn the identification tests for barium sulphate through a laboratory experiment or practical.

Aim:

To perform an identification test for barium sulphate.

Reference: Indian Pharmacopoeia (IP) 2010

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, dropper, rubber stopper, test tube stand, test tube holder, litmus paper, balance, etc.

Chemicals:
Barium sulphate (BaSO4), barium chloride (BaCl2), sodium carbonate (Na2CO3), lead acetate (Pb (C2H3O2)2), sulphuric acid (H2SO4), and hydrochloric acid (HCl), etc.

Theory of identification test for barium sulfate:

This identification of BaSO4 is usually based on the reactions of ions and cations present in the sample, by which we can determine the quality of the drug. Barium sulfate/sulphate is an inorganic compound. It is a crystalline white solid that is odorless. In water, organic solvents, and dilute acid and alkali solutions, it is insoluble.

Procedure:

For five minutes, boil 0.2 g BaSO4 in a 50% Na2CO3 solution. The salt is not soluble. By fusing it with anhydrous sodium carbonate or anhydrous potassium carbonate, it is converted into a less soluble salt. Filter the resulting mass after treating it with hot water. Perform barium tests on the residue collected on filter paper and for sulphate in filtrate collected after filtration.

BaSO3 + Na2CO3 → Na2SO4 + BaCO3

Identification tests for barium ion:

  1. Dissolve a portion of the residue in HCl and perform a flame test. The presence of barium ions is indicated by the yellowish-green color of the flame.
  2. Wash off the remaining residue with a small amount of water continuously. Wash off the other part of the residue with a small amount of water continuously. Add 5 mL of dilute hydrochloric acid to the residue and filter. To the filtrate, add 0.3 ml of dil. HCl. A white barium sulfate precipitate is formed, which is insoluble in nitric acid (HNO3).

Identification tests for sulphate ion:

  1. To a portion of the filtrate, add 01 ml of barium chloride solution. A white precipitate formed from the formation of barium sulfate.
  2. To 01 ml of filtrate, add 01 ml of lead acetate solution. A white precipitate formed from the formation of barium sulfate lead sulphate. Ammonium acetate solution and sodium hydroxide dissolve the precipitate.

Result:

The given sample is identified as barium sulphate.



Posted by No comments:
Labels:

Tuesday, April 19, 2022

Identification test of ammonium chloride

Learn the identification tests for ammonium chloride through a laboratory experiment or practical.

Aim:

To perform an identification test for ammonium chloride.

Reference: Indian Pharmacopoeia (IP) 2010

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, dropper, rubber stopper, test tube stand, test tube holder, litmus paper, balance, etc.

Chemicals:
Ammonium chloride (NH4Cl), sodium hydroxide (NaOH), sodium cobalt nitrate (CoN6Na3O12), light magnesium oxide (MgO), silver nitrate (AgNO3), ammonia solution, potassium dichromate(K2Cr2O7), diphenylcarbazide (C13H14N4O), hydrochloric acid (HCl), nitric acid (HNO3), sulphuric acid (H2SO4), and methyl red solution, etc.

Theory of identification test for ammonium chloride:

The purpose of identification tests is to determine the quality of a drug so that it can be used safely. This identification of NH4Cl is usually based on the reactions of ions and cations present in the sample, by which we can determine the quality of the drug.

Ammonium chloride comes in the form of colorless, or white crystalline powder, odorless, with a saline flavor. It is used as a diuretic, expectorant, and systemic acidifier. It is slightly soluble in ethanol and easily soluble in water.

Procedure:

Identification tests for ammonium ion:

  1. Heat a small amount of NH4Cl in a solution of sodium hydroxide.
  2. Add 3-4 drops of sodium cobalt nitrate (10% w/v) to the ammonium chloride solution.
  3. A yellow precipitate of ammonium cobalt nitrate is formed.
  4. To the solution of ammonium chloride, add 0.2 gm of light magnesium oxide. Pass a flow of air through the mixture and direct the gas which is evolved just below the surface of the mixture of 01.00 ml of HCl (0.1 M) and 0.05 ml of methyl red solution. The solution color changes to yellow.

Identification tests for chloride ion:

  1. Add 01.00 ml of dilute HNO3 solution to a 03.00 ml solution of ammonium chloride.
  2. Then add a few drops of silver nitrate solution, resulting in a white silver nitrate precipitate.
  3. When dilute ammonia is added, the precipitate dissolves due to the formation of a complex. (NH4CI + AgNO3 → AgCI+ NHNO3)
  4. In a test tube, add 0.2 gm potassium dichromate and 01 ml sulphuric acid with a little amount of ammonium chloride. Cover the mouth of the test tube with a filter-paper strip soaked with 0.1 mL of diphenylcarbazide solution. The color of the paper changes to a violet-red color.

Posted by No comments:
Labels:

Thursday, October 21, 2021

Identification test of copper sulphate

Learn the identification tests of copper sulphate through a laboratory experiment or practical.

Aim:

To perform identification tests of copper sulphate on a given sample.

Reference: Indian Pharmacopoeia (IP) 2010

Requirements:

Glasswares and miscellaneous:
Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, dropper, rubber stopper, test tube stand, test tube holder, and balance, etc.

Chemicals:
Sodium sulphide (Na2S), barium chloride (BaCl2), sodium hydroxide (NaOH), stannous chloride (SnCl2), ammonia (NH3), hydrochloric acid (HCL), and iodine (I2), etc.

Procedure for identification of copper sulphate:

  • Test-1: Take about 50.00 mg of the substance pour in 05.00 ml of water. Then add 01.00 ml of prepared solution of sodium sulphide, by which black precipitate is formed.
  • Test-2: Take about 50.00 mg of the substance pour in 05.00 ml of water, and then add 01.00 ml of ammonia solution. The precipitate was solubilized in excess of NH3 on acquiring a dark blue color.
  • Test-3: Take about 50.00 mg of the substance pour in 05.00 ml of water, and then add 01.00 ml prepared solution of dilute NaOH, by which blue precipitate is formed. In excess reagent, the precipitate is insoluble, and when heated, the precipitate turns black.
  • Test-4: Take about 50.00 mg of the substance dissolved in 05.00 ml of water. Add prepared 01.00 ml of dilute hydrochloric acid and then 01.00 ml of barium chloride solution, a white precipitate is formed.
  • Test-5: Add 00.10 ml of prepared iodine solution to the suspension produced in test-D; the suspension stays yellow however is decolorized by adding SnCl2 solution dropwise. Boil the mixture, no colored precipitate forms.
  • Test-6: Take about 50.00 mg of the substance dissolved in 05.00 ml of water. Then add 02.00 ml of prepared solution of lead acetate produces a white precipitate that is soluble in C2H7NO2 solution and NaOH is produced.

Observations:

  • Test-1: The addition of sodium sulphide solution resulted in the formation of a black precipitate.
  • Test-2: The Initial addition of ammonia solution resulted in the formation of a blue precipitate, which was solubilized in excess of ammonia, resulting in a deep blue solution.
  • Test-3: A white precipitate is created when dilute HCL and barium chloride solution are added.
  • Test-4: A yellow color was formed by adding iodine solution to the suspension, which is obtained in test 3. The addition of stannous chloride solution decolorized the color. Even after boiling the solution, the colored precipitate was not obtained.
  • Test-5: A white precipitate is formed by adding lead acetate to the test solution. After adding ammonium acetate and NaOH, the precipitate was solubilized.

Results:

The given sample complies with the tests 1 / 2 / 3 / 4 / 5 / 6 and does not comply with the tests 1 / 2 / 3 / 4 / 5 / 6 for the identification of copper sulphate as per IP 2010.

It suggests that the given sample is of ………………………...


FAQ (Frequently Asked Questions):


Which indicator is used in the assay of copper sulphate?
Generally, the starch indicator is used in the copper sulphate by iodometry.
Posted by No comments:
Labels:
Subscribe to: Posts (Atom)