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Friday, April 29, 2022

Preparation and standardization of 0.1 M oxalic acid

Learn about the preparation and standardization of 0.1 M oxalic acid solution through a laboratory experiment or practical.

Aim:

To prepare and standardize 0.1 M oxalic acid solution using 0.1 M solution of sodium hydroxide.


Requirements:

Glasswares: Burette, burette stand, conical flask, volumetric pipette, beaker, volumetric flask, funnel, glass rod, wash bottle, etc.
Chemicals: LR grade oxalic acid (C2H2O4), sodium hydroxide (NaOH), phenolphthalein indicator, etc.
Apparatus: Digital/analytical balance

Principle:

This titration is based on alkalimetry titration. When a strong base is titrated with a weak acid, the salt formed in the reaction that is not entirely hydrolyzed, and the pH of the final solution is about 07.00. Oxalic acid is a weak acid and is standardized by titration with a strong base, NaOH. To determine the endpoint phenolphthalein is used as an indicator. When NaOH is titrated with oxalic Acid, the following reaction occurs.

Preparation and standardization of oxalic acid

Preparation of 1M oxalic acid solution:

Weigh accurately 126.07 gm of oxalic acid and add 500 ml of distilled water. Once it has completely dissolved, make up the volume to 1000 ml.

Preparation of 1M NaOH solution:

Weigh accurately 40.00 gm of sodium hydroxide and add 500 ml of distilled water. Once it has completely dissolved, make up the volume to 1000 ml.

Titration procedure:

  • All glassware should be cleaned and dried according to standard laboratory procedures.
  • Before filling the burette for the titration, rinse it with distilled water and then pre-rinse it with a portion of the titrant solution. Pre-rinsing is required to make sure that all solution in the burette is the desired solution, not a contaminated or diluted solution.
  • Take the unknown stock solution of titrant in a clean and dry beaker then fill the burette using the funnel.
  • Remove air bubbles from the burette and adjust the reading to zero.
  • Take 10.00 ml of prepared 1M NaOH solution and pour it into a conical flask.
  • Add 2-3 drops of phenolphthalein indicator.
  • Titrate the sample solution with the oxalic acid solution until the pink color disappears.
  • Properly record the readings of the burette.
  • To get accurate results, repeat the titration three times.
  • Take their mean and calculate the molarity of oxalic acid.

Observation table:

Sr. No.

Content in conical flask

Burette reading

Volume of titrant used (ml)

Initial

Final

1

 

 

 

 

2

 

 

 

3

 

 

 

 

Mean:

Calculations:

The Molarity of Oxalic Acid is calculated using the formula : M1V1=M2V2
where ,
V1 is the volume of 1M NaOH solution = 10 ml
M1 is the molarity of NaOH solution = 1M
V2 is the volume of oxalic acid solution
M2 is the molarity of oxalic acid =?
Therefore, M2=M1V1/V2

Result:

The strength of the prepared oxalic acid solution was found to be_____M.
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Preparation and standardization of 0.1 M potassium iodate

Learn about the preparation and standardization of 0.1 M potassium iodate solution through a laboratory experiment or practical.

Aim:

To prepare and standardize 0.1 M potassium iodate solution using 0.1 M solution of sodium thiosulphate.

Requirements:

Glasswares: Burette, burette stand, conical flask, volumetric pipette, beaker, volumetric flask, funnel, glass rod, wash bottle, etc.

Chemicals: AR grade potassium iodate (KIO3), potassium iodide (KI), sulphuric acid (H2SO4), sodium thiosulphate (Na2S2O3), starch, etc.

Apparatus: Digital/analytical balance, and Ultrasonicator.

Preparation of starch solution:

Click here to get the procedure.

Preparation of 0.1M potassium iodate solution:

Take 21.4 gm of previously dried potassium iodate in 500 ml of water. Once it has completely dissolved, make up the volume to 1000 ml.

Titration procedure:

  • All glassware should be cleaned and dried according to standard laboratory procedures.
  • Before filling the burette for the titration, rinse it with distilled water and then pre-rinse it with a portion of the titrant solution. Pre-rinsing is required to make sure that all solution in the burette is the desired solution, not a contaminated or diluted solution.
  • Take the unknown stock solution of titrant in a clean and dry beaker then fill the burette using the funnel.
  • Remove air bubbles from the burette and adjust the reading to zero.
  • Take 25.00 ml of prepared solution of potassium iodate into 200 ml of water. In 20.00 ml of this solution, add 02.00 g of potassium iodide and 10.00 ml of 1M sulfuric acid.
  • Add 01.00 ml of the starch indicator.
  • Titrate the sample solution with 0.1M sodium thiosulphate until the endpoint is reached. The actual endpoint indicates by colorless to blue starch-iodine complex.
  • Properly record the readings of the burette.
  • To get accurate results, repeat the titration three times.
  • Take their mean and calculate the molarity of ferrous ammonium sulphate.
  • 01 ml of 0.1M sodium thiosulphate is equivalent to 0.003566 gm of KIO3.

Observation table:

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Preparation and standardization of 0.1 M ferrous ammonium sulphate

Learn about the preparation and standardization of 0.1 M ferrous ammonium sulfate solution through a laboratory experiment or practical.

Aim:

To prepare and standardize 0.1 M ferrous ammonium sulphate solution using 0.1 M solution of ceric ammonium sulphate.

Requirements:

Glasswares: 
Burette, burette stand, conical flask, volumetric pipette, beaker, volumetric flask, funnel, glass rod, wash bottle, etc.

Chemicals:
LR grade ferrous ammonium sulphate (FeH8N2O8S2), ceric ammonium sulphate ((NH4)4Ce (SO4)4), ortho-Phenanthroline (C36H24FeN6+2), sulphuric acid (H2SO4), etc.

Apparatus: 
Digital/analytical balance, and Ultrasonicator.

Preparation of 0.1 M ferrous ammonium sulphate solution:

Take 160 ml of distilled water, add 40 ml of sulphuric acid, and once it is cooled then weigh 40 gm of ferrous ammonium sulphate and add it. Once it has completely dissolved, make up the volume to 1000 ml.

Titration procedure:

  • All glassware should be cleaned and dried according to standard laboratory procedures.
  • Before filling the burette for the titration, rinse it with distilled water and then pre-rinse it with a portion of the titrant solution. Pre-rinsing is required to make sure that all solution in the burette is the desired solution, not a contaminated or diluted solution.
  • Take the unknown stock solution of titrant in a clean and dry beaker then fill the burette using the funnel.
  • Remove air bubbles from the burette and adjust the reading to zero.
  • Take 25.00 ml of prepared solution of ferrous ammonium sulphate and pour it into a conical flask.
  • Add 2 drops of ortho-Phenanthroline indicator.
  • Titrate the sample solution with 0.1M ceric ammonium sulfate until the endpoint is reached. The actual endpoint of the reaction is red color changes to a blue one.
  • Properly record the readings of the burette.
  • To get accurate results, repeat the titration three times.
  • Take their mean and calculate the molarity of ferrous ammonium sulphate.
  • 01 ml of ceric ammonium sulphate is equivalent to 0.03921 gm of Fe (NH4)2(SO4)2,6H2O.

Observation table:
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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.
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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.
No comments:

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.
No comments:

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.
No comments:

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.
No comments:

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.
No comments:

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.
No comments:

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.


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