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external indicator is required in diazotization as to observe the end point of the reaction. internal indicators cannot give the endpoint because they may form complexes which may cause hindrance. for example, in the assay of sulfa drugs, iodine-starch paste is used as external indicator, because if we add iodine paste in the conical flask it will react with the reactants and give the blue-black coloration in the beginning of the actions, which will not tell the end point of the reaction. instead, the iodine-starch paste is applied in a paper, and the compound from the burette is added in small quantities into the sulfa drug solution, and after every few milliliters a drop of solution from the conical flask is dropped on the iodine-starch paste, when there is sudden change in colour, the addition from the burette is stopped. and observations are made.
External indicators such as starch are used in diazotization titrations to provide a visible color change as a signal that the endpoint has been reached. This helps in accurately determining the equivalence point of the titration and thus the concentration of the analyte being measured.
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Why in titration of kmno4 no indicator is used?
In the titration of KMnO4, no indicator is used because KMnO4 is a self-indicating titrant. It undergoes a color change from purple to colorless (or brown) at the endpoint of the titration, which makes it unnecessary to add an external indicator. The precise endpoint can be easily detected visually, making the use of an indicator redundant.
What is double indicator titration?
Double indicator titration is a type of titration method that involves the use of two different indicators to determine the endpoint of the reaction. The first indicator changes color near the starting pH of the titration, while the second indicator undergoes a distinct color change at or near the endpoint of the titration. This technique is commonly used in complexometric titrations to determine the concentrations of metal ions in a solution.
How much phenolphthalein indicator should be used?
Typically, 1-2 drops of phenolphthalein indicator are sufficient to use in an acid-base titration experiment. It is important not to use too much indicator, as it can affect the accuracy of the titration results.
What is Fajan's method of argentometric titration?
Fajan's method of argentometric titration involves the use of potassium chromate as an indicator to detect the end point of a titration between silver ions and chloride ions. The indicator changes color from yellow to red when all the chloride ions have reacted with the silver ions, marking the end point of the titration.
Why no use indicator in the standardizing potassium permanganate titration?
In the standardization of potassium permanganate titration, an indicator is not used because the titration is self-indicating. This means the solution being titrated changes color at the end point, so an additional indicator is not necessary. It is important to carefully observe the color change to ensure accurate titration results.
Why in titration of kmno4 no indicator is used?
In the titration of KMnO4, no indicator is used because KMnO4 is a self-indicating titrant. It undergoes a color change from purple to colorless (or brown) at the endpoint of the titration, which makes it unnecessary to add an external indicator. The precise endpoint can be easily detected visually, making the use of an indicator redundant.
What is double indicator titration?
Double indicator titration is a type of titration method that involves the use of two different indicators to determine the endpoint of the reaction. The first indicator changes color near the starting pH of the titration, while the second indicator undergoes a distinct color change at or near the endpoint of the titration. This technique is commonly used in complexometric titrations to determine the concentrations of metal ions in a solution.
How much phenolphthalein indicator should be used?
Typically, 1-2 drops of phenolphthalein indicator are sufficient to use in an acid-base titration experiment. It is important not to use too much indicator, as it can affect the accuracy of the titration results.
What is Fajan's method of argentometric titration?
Fajan's method of argentometric titration involves the use of potassium chromate as an indicator to detect the end point of a titration between silver ions and chloride ions. The indicator changes color from yellow to red when all the chloride ions have reacted with the silver ions, marking the end point of the titration.
Why no use indicator in the standardizing potassium permanganate titration?
In the standardization of potassium permanganate titration, an indicator is not used because the titration is self-indicating. This means the solution being titrated changes color at the end point, so an additional indicator is not necessary. It is important to carefully observe the color change to ensure accurate titration results.
What is the indicator use in potentiometric titration?
The indicator used in potentiometric titrations is typically a pH electrode. By measuring changes in pH during the titration process, the endpoint of the titration can be determined accurately. The pH electrode provides a continuous measurement of the solution's pH, allowing for a precise determination of the equivalence point.
Describe a method to visually detect the end point of a titration without the use of instruments?
One way to visually detect the end point of a titration without instruments is to use an indicator that changes color at the equivalence point. For example, phenolphthalein changes from pink to colorless at the endpoint of an acid-base titration. Another method is to add the titrant drop by drop and look for a sudden color change in the solution.
Why you use phenolphethalein indicator in titration?
Phenolphthalein is used as an indicator in titrations to visualize the endpoint of an acid-base titration. It changes color from colorless to pink in a basic solution, indicating the completion of the reaction between the acid and base. This change is easily detectable and helps to accurately determine the equivalence point of the titration.
How do you get accurate titration value?
To get an accurate titration value, ensure that all reagents are standardized and accurately measured, use an appropriate indicator, perform the titration slowly and carefully, and repeat the titration for consistency. Calibration and proper maintenance of equipment are also important for accuracy.
When to use back-titration instead of direct titration?
Back-titration is useful when the analyte reacts slowly or not at all with the indicator used in direct titration. It is also used when the endpoint of the direct titration is not clearly visible. Additionally, back-titration is employed when the analyte is present in very low concentrations and requires a larger amount of titrant for direct titration.
What equipment is used in titration at school?
In a school laboratory titration, you would typically use a burette to deliver the titrant, a pipette to measure the volume of the analyte, an Erlenmeyer flask to hold the analyte, a magnetic stirrer for mixing, and an indicator to show the endpoint of the titration.
What is the best way to choose an indicator for use in titration?
The best way to choose an indicator for titration is to select one with a color change that closely matches the pH range of the equivalence point of the reaction being titrated. This ensures that the indicator will provide a clear and distinct color change when the reaction reaches completion. Additionally, consider factors such as the solubility of the indicator in the solution and any interference it may have with the titration reaction.
