How to Prepared and Standardize of 0.5 N Potassium Hydroxide, Alcoholic Volumetric Solution.

How to Prepared and Standardize of 0.5 N Potassium Hydroxide, Alcoholic Volumetric Solution.


                                       

                                     



Preparation of 0.5 N Potassium Hydroxide,Alcoholic Volumetric solution


➤ Glass ware and instruments required.

Beaker, Glass stirrer, Graduated Pipettes, Graduated cylinder, Analytical balance, Sucker, Volumetric flask, Burette, Conical Flask, Fume hood.


➤ Reagents required.

Potassium Hydroxide Reagent Grade, 
Mol Wt. :- KOH,  56.11
Hdrochloric Acid Volumetric Soliution (0.5 N),
Phenolphthalein Indicator,
Aldehyde Free Alcohol,
Phenolphthalein Indicator.


➤ Preparation.

Weigh 35 g of potassium hydroxide reagent grade in 100 ml beaker and dissolve in 20 ml of water. Transfer carefully to 1000 ml volumetric flask and make up to the volume with aldehyde free alcohol. Allow the solution to stand in a tightly stoppered bottle for 24 hours. Then quickly decant the clear supernatant liquid in to a suitable, tight container.



➤ Standardization.

Pipette out 25ml of 0.5 N / 0.5 M hydrochloric acid VS into a   250 ml conical flask. Dilute with 50 ml of water, add two drops of phenolphthalein solution, and titrate with alcoholic potassium hydroxide solution until a permanent pale pink colour is produced.


➤ Calculations.


                   ml , HCl  x N/M HCl

N/M = ---------------------------------------

                             ml,  KOH                 







How to prepare and Standardize 0.05 N Edeatate Disodium (EDTA) volumetric Solution.

How to prepare and Standardize 0.05 N Edeatate Disodium (EDTA) volumetric Solution.


                                                             


Preparation of 0.05 N Edeatate Disodium (EDTA) Solution volumetric solution.

➤ Glass ware and instruments required.

Beaker, Glass stirrer, Graduated Pipettes, Graduated cylinder, Analytical balance, Sucker, Volumetric flask, Burette, Conical flask, Fume hood.

 ➤ Reagents required. 

Edeatate Disodium Reagent grade
Calcium Carbonate PS (previously dried for 2 hour at 105°)
Hydrochloric Acid Dilute
Sodium Hydroxide 1 Normal
Hydroxy napthol blue Indicator


➤ Preparation.

Weigh 18.6 g Edeatate Disodium / Disodium Edeatate reagent grade in 1000 ml volumetric flask. Dissolve in sufficient water by warming, cool and dilute up to the mark with water.


➤ Standardisation.

Accurately weigh about 0.1 g calcium carbonate PS, previously dried for 2 hour at 105°, in to a 250 ml conical flask. Dissolve in 10 ml water and 2 ml dilute hydrochloric acid and dilute to about 100 ml with water. To this solution add 15 ml 1N sodium hydroxide solution and 0.2 g of hydroxy napthol blue indicator and titrate with Edeatate Disodium / Disodium Edeatate solution till the red colour of solution changes to blue colour. 


➤ Calculations.

                             g  CaCO3  x  0.05
M = --------------------------------------------------
                   0.005  x   Burette reading  in ml 







How to prepare and Standardize 0.1 N Ammonium Thiocynate acid volumetric Solution.


How to prepare and Standardize 0.1 N Ammonium Thiocynate acid volumetric Solution.

                                                                  
                   
                                                    



Preparation of 0.1 N Ammonium Thiocynate volumetric solution.


➤ Glass ware and instruments required.

Beaker, Glass stirrer, Graduated Pipettes, Graduated cylinder, Analytical balance, Sucker, Volumetric flask, Burette, Conical flask, Fume hood.

 
➤ Reagents required.

Ammonium Thiocynate Reagent grade
Molecular Wt. NH4SCN, 76.12
Silver Nitrate volumetric solution
Nitric Acid 
Ferric ammonium sulphate Solution


➤ Preparation.

Weigh about 8 g of ammonium thiocynate reagent grade in 1000 ml in 1000 ml volumetric flask. Dissolve and dilute with water. Filter the solution, if it is not clear.


➤ Standardisation.

Pipette out 25 ml of standard 0.1 N silver nitrate VS into glass stoppered flask. Dilute with 50 ml of water, then add 2 ml of nitric acid and 2 ml of ferric ammonium sulphate solution, and titrate with the ammonium thiocynate solution to the first appearance of red brown colour. 


➤ Calculations.

                              ml   AgNO3  x  N / M  AgNO3
N / M = ----------------------------------------------------------------------
                       ml  NH4SCN solution  [ Burette reading in ml ]

 




HOW TO PREPARE DOCUMENTATION IN INDUSTRY

                              DOCUMENTATION

INTRODUCTION :-

Documentation is covered by the Drugs Cosmetic Act 1940/Rules 1945 and is explained in schedule U of the said act.

Any anomoly in the documentation, if not explained properly by the staff, is deemed to be violation and the company is liable for penal action. Hence documentation must be taken as an individual responsibility and must be given the importance, it deserves.

Documentation is relevant in every phase of production facility, be it stores department to receive and dispense the material or Production department to produce the formulation or Quality Control department to carry out raw material/in process/finished product testing or Quality Assurance department to release the final goods to the customer.

Proper documentation is a primary requirement of CGMP (Current Good Manufacturing Practices) and it is indeed imperative that each member of the staff must be careful about documents under his/her control. The emphasis must be on zero defect, so that the final document kept as a record, will be defect free.

PARTICULARS TO BE SHOWN IN MANUFACTURING RECORDS FOR SUBSTANCES OTHER THAN PARENTERAL PREPARATION IN GENERAL

1.      Serial Number.

2.      Name of the Product.

3.      Reference of Master Formula Records.

4.      Lot /Batch Size.

5.      Lot / Batch Number.

6.      Date of commencement of manufacture and date of completion of manufacture and the assigned date of expiry.

7.       Name of all ingredients, specifications quantities required for the lot/Batch size and quantities actually used. All weighings and measurements shall be carried out by   a responsible person and initialed by him and shall be counter checked and signed by the competent technical staff under whose personal supervision the ingredients are used for manufacture.

8.      Control Numbers of raw materials used in the formulation.

9.      Date. time and duration of mixing.

10.    Detail of environmental controls like room temperature, relative humidity.

11.    Date of granulation, wherever applicable.

12.    Theoretical weight and actual weight of granules/powder blend.


13.    Records of in-processes controls (Periodically whenever necessary).
(a)          Uniformity of mixing.
(b)          Moisture content of granules/powder in case of Tablet/Capsules.
(c)           pH of solution in case of liquid.
(d)          Weight variation.
(e)          Disintegration time.
(I)            Hardness.
(g)          Friability test
(h)          Leak test in case of strip packing.
(i)            Filled volume of liquids.
j)             Quantity of tablets/capsules in the final container.
(k)           Content of ointment in the filled containers.

14.    Date of compression in case of Tablets / date of filling in case of capsules.

15.    Date of sealing/coating/polishing in case of capsules/tablets wherever applicable.

16.    Reference to analytical Report number stating the result of test and analysis.

17.    Separate records of the disposal of the rejected batches and of batches withdrawn from the market

18.    The theoretical yield and actual productions yield and packing particulars indicating the size and quantity of finished packings.

19.    Specimen of label / strip, carton with batch coding information like Batch Number, date of manufacture. date of expiry, retail price as applicable. stamped thereon and inserts used in the finished packings.

20.    Signature with date of competent technical staff responsible for the manufacture.

21.    Counter-signature of the head of the testing units or other approved person-in- charge of testing for having verified the batch records and for having released the batch for sale and distribution. the quantity released and date of release.

22.    Date of release of finished packings and quantity released for sale and distribution

23.    Quantity transferred to warehouse.

24.     For Hypodermic tablets and ophthalmic preparations which are required to be manufactured under  aseptic conditions, records shall be maintained indicating the precautions taken during the process of manufacture to ensure that aseptic conditions are maintained.

                                                 RECORDS OF RAW MATERIALS

Records in respect of each raw material shall be maintained indicating the date of receipt, invoice number. name and address of manufacturer/supplier, batch number, quantity received, pack size. date of manufacture date of expiry, if any, date of analysis and release/rejection by quality control, analytical report number. with special remarks. if any quantity issued, date of issue and the particulars of the name and batch numbers of products for the Manufacture of which issued and the proper disposal of the stocks.

                         PARTICULARS TO BE RECORDED IN THE ANALYTICAL RECORDS 

                                                     TABLETS AND CAPSULES.


1.      Analytical report number.

2.      Name of the sample.

3.      Date of receipt of sample.

4.      Batch/Lot number.

5.      Protocols of tests applied.
(a) Description.
(b) Identification.
(c) Uniformity of weight.
(d) Uniformity of diameter (if applicable).
(e) Disintegration test (time in minutes).
(I)  Any other tests.
(g) Results of Assay.

Note : Records regarding various tests applied (including readings and calculations) should be maintained and reference to these records should be entered in Col. 5 above whenever necessary.

6.      Signature of the Analyst.

7.      Opinion and signature of the approved Analyst.

                                                    FOR OTHER DRUGS 


1.      Analytical report number.

2.      Name of the sample.

3.      Batch/Lot number.

4.      Date of receipt of sample.

5.      Protocol of tests applied.
(a) Description.
(b) Identification.
(c) Any other tests
 (d) Results of Assay.

Note : Particulars regarding various test applied (including readings and calculations) shall be maintained and necessary reference to these records shall be entered in Column 5 above, wherever necessary.

6.      Signature of the Analyst.

7       Opinion and signature of the approved Analyst.

                                                                          

                                                                 RAW MATERIAL


1.      Serial number.

2.      Name of the materials.

3.      Name of the manufacturer/supplier.

4.      Quantity received.

5.      Invoice / Challan number and date.

6.      Protocols of tests applied.


                                          CONTAINER, PACKING MATERIAL


1.      Serial number.

2.      Name of the item.

3.      Name of the manufacturer/supplier.

4.      Quantity received.

5.      Invoice / Challan number and date.

6.      Results of tests applied.

Note : Particulars regarding various test applied shall be maintained and necessary reference to these records shall be entered in Column 6 above, wherever necessary.

7.      Remarks.

8.      Signature of the examiner.


                                              GENERAL ANOMOLIES



Some of the general anomolies observed in the BMR/BPR by Q.A., have been included in the following list

a)   Overwriting and excessive cancellations of entries.

b)   Signature of Production officer, competent person missing from the document.

c)   Entries missed on the document, although duly signed by Production officer.

d)   Wrong entries of container numbers.

e)   Wrong subtraction of Gross and Tare weights.

f)    Date column not filled.

g)   Sifter number not ticked. 

h)   Cleanliness record not completely filled, although document is duly signed by the production officer.

i)    Remark column not filled. If there is no relevant remark, the relevant column can have 'Nil' or ' -' as an entry.

j)     Some of the operations not bearing the initials of the operators involved in the operation; although signature of Production officer is available e.g. mixing operation in Norflox tablets.

k)   A series of humidity observations having only one signature at the top. All the observations must be individually signed.

l)    Bulk density, Friability and Sieve analysis figures are available; but the raw data is not available.
m) Average weight of the tablet after coating is calculated, but the methodology of calculation was not shown on the BMR.

n)   The word 'Production officer', was missing after conclusion of certain important steps like inspection and hence the relevant page was not signed by the "Production officer".

o)   Temperature not recorded during drying operation of one of the lots.

p)   BMR No./A.R.No. not mentioned.

q)   Soaking time does not match.

r)    Compressed air "Dew point" not recorded.

s)   ‘Checked by' not signed.

t)    Batch summary sheet not filled.

u)   The timings in the case of rinsing of pressure vessel in Aerosol manufacturing is recorded less than the timing required as per SOP.

v)   Reconciliation of cans does not tally.

w) The total weight of foil does not tally.

x)   Relevant S.O.P numbers were not ticked.

y)   In the rejected analysis sheet of BPR, the total is wrong or the total is available, without individual entries. Percentage of rejects calculated wrongly.

                                             

                                


VOLUMETRIC SOLUTIONS

                                                VOLUMETRIC SOLUTIONS

A volumetric solution refers to a solution prepared in a precise, known volume for use in quantitative chemical analysis, particularly in titrations or when making precise dilutions. Volumetric solutions are commonly used in laboratory work for experiments that require highly accurate measurements of concentration. The process of preparing and using these solutions follows standardized protocols to ensure reproducibility and accuracy.

Key Aspects of Volumetric Solutions:

  1. Definition:

    • A volumetric solution is one where the solute (solid or liquid) is dissolved in a solvent (typically water or another appropriate solvent) to prepare a solution of a known volume. The exact concentration (molarity or normality) of the solution is determined and is crucial for its intended analytical purpose.
  2. Concentration:

    • The concentration of a volumetric solution is typically expressed in units such as molarity (M), normality (N), or molality (m). The concentration can be calculated using the formula:

      C=Amount of solute (in moles)Volume of solution (in liters)C = \frac{\text{Amount of solute (in moles)}}{\text{Volume of solution (in liters)}}

    For example, a 1 M (1 mol/L) solution means there is 1 mole of solute per liter of solution.

  3. Preparation of Volumetric Solutions:

    • Weighing the Solute: The first step in preparing a volumetric solution is to carefully weigh the solid solute (e.g., a salt or acid) using an analytical balance to ensure precision.
    • Dissolving the Solute: The weighed solute is then dissolved in a small amount of solvent in a container (such as a beaker or flask). If using a liquid solute, an appropriate volume is measured using a pipette or burette.
    • Transferring to a Volumetric Flask: After the solute is fully dissolved, the solution is transferred to a volumetric flask, which is a calibrated container designed to hold a precise volume of liquid (e.g., 1 L, 500 mL). The flask is filled to the calibration mark with solvent, ensuring that the final volume is accurate.
    • Mixing: The solution is thoroughly mixed to ensure uniform concentration throughout the solution.
  4. Types of Volumetric Solutions:

    • Primary Standard Solutions: These are solutions made from substances that can be accurately weighed and are highly pure. They are used to prepare solutions of known concentration, which can then be used for titrations or other analytical processes.
      • Example: A solution of sodium carbonate (Na₂CO₃) is commonly used as a primary standard in acid-base titrations.
    • Secondary Standard Solutions: These are solutions whose concentration has been determined using a primary standard. Secondary standards are often more convenient for regular laboratory use, as preparing primary standards can be tedious.
      • Example: A hydrochloric acid (HCl) solution that is standardized against a primary standard like sodium carbonate.
  5. Titration:

    • Volumetric solutions are commonly used in titrations, where a solution of known concentration is used to determine the concentration of an unknown solution. In a titration, the volume of the standard solution required to react completely with the analyte (the solution being tested) is measured, and from that, the concentration of the unknown solution is calculated.
  6. Types of Common Volumetric Solutions:

    • Acid-Base Solutions: These are solutions of acids or bases, such as hydrochloric acid (HCl), sodium hydroxide (NaOH), or sulfuric acid (H₂SO₄), used in acid-base titrations.
    • Redox Solutions: These involve solutions that can undergo oxidation-reduction reactions, like potassium permanganate (KMnO₄) or iodine (I₂), used in redox titrations.
    • Complexometric Solutions: These solutions contain complexing agents (e.g., EDTA) used in complexometric titrations to determine metal ions in a sample.
    • Precipitation Solutions: Solutions that participate in precipitation reactions, like silver nitrate (AgNO₃), which is used in halide ion determination via precipitation titration.
  7. Standardization:

    • Standardization is the process of determining the exact concentration of a volumetric solution, typically by titrating it against a known standard (often a primary standard substance).
    • For example, a sodium hydroxide (NaOH) solution can be standardized by titrating it against a known concentration of hydrochloric acid (HCl).
    • Standardization helps ensure that the solution's concentration is accurate and can be used confidently in subsequent experiments.
  8. Storage and Stability:

    • Volumetric solutions should be stored in tightly sealed containers to avoid contamination or evaporation. Depending on the chemical nature of the solute and solvent, some solutions may need to be stored in dark places (to avoid degradation by light) or at certain temperatures.
    • Some solutions, particularly those that are unstable (e.g., some peroxide solutions or reducing agents), may need to be prepared fresh or stored in a way that minimizes decomposition.
  9. Factors to Consider:

    • Purity of the Solute: Ensure that the solute is of high purity and free from contaminants, as this can affect the accuracy of the volumetric solution.
    • Temperature: Temperature can influence the volume of liquids (expansion or contraction) and may also affect the solubility of the solute. Therefore, it is important to prepare and store volumetric solutions at a constant, known temperature.

Example: Preparing a Volumetric Solution of Sodium Hydroxide (NaOH)

  1. Calculate the Amount of NaOH Needed: To prepare a 1.0 M solution of NaOH in 1 L of water, calculate the amount of NaOH required:

    • Molar mass of NaOH = 40.00 g/mol
    • Required concentration = 1.0 M (1 mol/L)
    • Volume = 1 L

    Amount of NaOH = 1.0mol/L×40.00g/mol=40.00g1.0 \, \text{mol/L} \times 40.00 \, \text{g/mol} = 40.00 \, \text{g}

  2. Weigh the NaOH: Weigh 40.00 g of solid sodium hydroxide (NaOH) using an analytical balance.

  3. Dissolve the NaOH: Dissolve the NaOH in a small amount of distilled water in a beaker.

  4. Transfer to Volumetric Flask: After the NaOH is fully dissolved, transfer the solution to a 1-liter volumetric flask. Rinse the beaker with additional distilled water and add the rinse water to the flask to ensure all the solute is transferred.

  5. Fill to the Mark: Fill the volumetric flask with distilled water to the 1 L mark. Ensure the meniscus (the curved surface of the liquid) is exactly at the mark when viewed at eye level.

  6. Mix the Solution: Cap the flask and invert it several times to ensure thorough mixing.

Conclusion:

Volumetric solutions are critical in analytical chemistry for determining concentrations accurately. They are prepared by dissolving a known quantity of solute in a specific volume of solvent. Precision in the preparation, standardization, and storage of these solutions ensures reliable results in various chemical analyses, including titrations, reactions, and quantifications.

WEGHING BALANCE

Analytical Weighing Balance and it's Standardization :

An analytical weighing balance is a highly precise instrument used to measure small masses with great accuracy. These balances are typically used in laboratories for applications where exact weight measurements are crucial, such as in chemical analysis, pharmaceutical research, and materials testing.

Key Features of Analytical Weighing Balances:

  1. High Precision: Analytical balances are capable of measuring mass with accuracy to at least 0.0001 g (0.1 mg), and some models can go even further, achieving resolutions of 0.00001 g (0.01 mg).

  2. Sensitivity: The sensitivity of these balances is very high, which means they can detect very small changes in mass. This makes them suitable for weighing small quantities of substances, such as chemicals in laboratory experiments.

  3. Draft Shield: Most analytical balances are equipped with a draft shield or enclosure to prevent air currents from affecting the measurement. The shield helps maintain the accuracy of the reading by minimizing environmental factors like wind, vibrations, or static electricity.

  4. Calibration: Analytical balances usually have an internal calibration system or an external calibration weight for periodic calibration to maintain accuracy over time. Many models also support automatic calibration.

  5. Digital Display: Modern analytical balances come with a digital display that shows the weight measurement in various units, such as grams, milligrams, and carats. Some models also offer tare functionality (subtracting the weight of a container or other items) for more accurate net mass readings.

  6. Environmental Conditions: To achieve the highest accuracy, analytical balances must be used in controlled environments. Temperature, humidity, and air pressure can all impact the measurements, so balances are often used in specially designed labs with stable conditions.

  7. Capacity: While analytical balances are designed for high accuracy, their capacity is typically lower than that of other types of balances (such as precision balances). The typical range is between 100 g to 200 g, although some models can weigh larger items (up to a few kilograms).

  8. Applications: Analytical balances are widely used in industries such as pharmaceuticals (for drug formulation and quality control), food science (for ingredient measurement and analysis), and materials science (for precise measurements of samples).

Typical Specifications:

  • Readability: 0.1 mg (0.0001 g) or better
  • Capacity: 100 g to 200 g, though models with higher capacities are available
  • Pan Size: Typically around 80-120 mm in diameter
  • Stabilization Time: 1-3 seconds for the reading to stabilize, depending on the model and environment
  • Taring Function: Allows subtraction of the container’s weight to get the weight of the sample only
  • Units of Measure: Grams (g), milligrams (mg), carats (ct), pounds (lbs), etc.

Examples of Use Cases:

  • Pharmaceutical labs: Measuring precise amounts of active ingredients for drug production.
  • Chemical laboratories: Accurately weighing reagents for reactions and analyses.
  • Food industry: Ensuring proper ingredient ratios for formulations or packaging.
  • Academic research: Weighing minute quantities of samples for experiments that require precise data.

Maintenance Tips:

  • Leveling: Ensure the balance is placed on a stable, level surface, as improper leveling can lead to inaccurate measurements.
  • Regular Calibration: Even if the balance has automatic calibration, it's good practice to calibrate the balance with a known standard periodically.
  • Cleanliness: Regularly clean the balance to prevent dust, oils, or other contaminants from affecting the measurements.
  • Environmental control: Keep the area free from vibrations, drafts, and other disturbances.

    Standardization of an analytical weighing balance:  involves ensuring that the balance provides accurate and consistent measurements. This process is essential for maintaining the reliability of the instrument, especially when performing precise measurements in scientific and industrial settings.

    Key Steps for Standardizing an Analytical Weighing Balance:

    1. Calibration:

      • Internal Calibration: Many modern analytical balances have an internal calibration system that automatically adjusts the balance. This is typically done using a built-in weight.
      • External Calibration: For higher accuracy, an external calibration weight with known mass (traceable to national or international standards, such as OIML or NIST) is used. This method ensures the balance is correctly calibrated at specific intervals or when environmental conditions change.
    2. Adjustment:

      • Adjustments are made if the calibration shows that the balance is not reading accurately. This could involve software settings or mechanical adjustments, depending on the model.
    3. Use of Certified Weights:

      • Certified calibration weights should be used during external calibration. These weights have known and verified values and are traceable to national or international standards, ensuring the accuracy of the calibration process.
    4. Temperature and Humidity Control:

      • Analytical balances are sensitive to environmental conditions. Ensure the temperature and humidity are within recommended ranges. If the environment fluctuates, the balance may need to be recalibrated.
    5. Taring:

      • Taring the balance (zeroing out the weight of containers or additional items) ensures that only the sample's mass is measured. This should be done before each weighing.
    6. Documentation:

      • Calibration results and any adjustments made should be documented for traceability, particularly in regulated environments like pharmaceutical labs or quality control settings.
    7. Verification:

      • After calibration, the balance should be verified using a known test weight to ensure its accuracy is within the acceptable tolerance range (often specified in the balance’s user manual).
    8. Regular Checks:

      • Periodic checks (e.g., daily or weekly) using known reference weights help verify that the balance remains accurate over time. The frequency depends on usage and the environment.
    9. Environmental Considerations:

      • The balance should be placed in a draft-free, vibration-free environment with stable temperature and humidity levels. Balances often come with a draft shield to mitigate air currents, but ensuring the room conditions remain stable is still crucial.
    10. Maintenance and Cleaning:

      • Regular maintenance, including cleaning the weighing pan and ensuring no debris or contaminants affect measurements, is essential for consistent standardization.

How to Prepared and Standardize of 0.1 N Cerric Ammonium Nitrate Volumetric Solution

How to Prepared and Standardize of 0.1 N Cerric Ammonium Nitrate Volumetric Solution


                                                        
                                                            


Preparation of 0.1 Cerric Ammonium Nitrate Volumetric solution



➤ Glass ware and instruments required.

Beaker, Glass stirrer, Graduated Pipettes, Graduated cylinder, Analytical balance, Sucker, Volumetric flask, Burette, Conical Flask, Fume hood.


➤ Reagents required.

Cerric Ammonium Nitrate Reagent Grade
Molecular Wt. :- Ce(NO3)4.2NH4NO3,   548.22
Sulphuric Acid Reagent grade,
Arsenic trioxide PS Previosly dried for 1 hour at 105°, 
Sodium Hydroxide,
Sulphuric Acid Dilute,
Osmic solution acid solution,
Ferroin sulphate solution.


➤ Preparation.

Shake a solution containing 56 ml of sulphuric acid reagent grade and 54.82 g of ceric ammonium nitrate reagent grade for 2 minutes and carefully add 5 successive 100 ml quantities of water, shaking after each addition. Dilute the clear solution to 1000 ml with water. Standardize the solution after 10 days. On the day of use, standardize the solution.


➤ Standardization.

Accurately weigh about 0.2 g arsenic trioxide PS, previously dried for one hour at 105°,  in 500 ml conical flask. Wash down the inner walls of the flask with 25 ml of 8% w/v solution of sodium hydroxide, swirl to dissolve, add 100 ml of water and mix. Add 30 ml of dilute sulphuric acid, 0.15 ml of osmic acid solution, 0.1 ml of ferroin sulphate solution. Titrate the solution with 0.1 N / 0.1 M ceric ammonium nitrate solution until the pink colour of the solutiom changes sharply to pale blue.


➤ Calculations.

                                                   g  AS2O3  x  0.1
             N / M =    --------------------------------------------------
                                     0.004946  x   Burette reading in ml 












How to Prepared and Standardize of 0.5 N Potassium Hydroxide, Alcoholic Volumetric Solution.

How to Prepared and Standardize of 0.5 N Potassium Hydroxide, Alcoholic Volumetric Solution.                                         ...