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Why is phenolphthalein an appropiate indicator for back titration?
Wiki User
∙ 15y ago
it's not in all cases.
Only for titration of weak acids.
Wiki User
∙ 15y ago
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Why is a back titration sometimes used for an analysis rather than a direct titration?
Back titrations are used when a reaction occurring in the conical flask can not be detected using an indicator such as phenolphthalein. So, after this titration has been performed, the 'excess' is then titrated with something that can be detected more easily using phenolphthalein etc.
When to use back-titration instead of direct titration?
When you have passed the tipping point and the color indicator turns from it's color to the clear color of the original solution. Then you back titrate to color again.
What are complexometric titration method?
Direct titration, Indirect titration, back titration, replacement titration and so on
What is a back titration?
A back titration is a form of titraiton in which an excess of standard reagent is added and then the reverse of the titration is carried out.
What difference between titration and back titration?
In fact, a back titration is carried out as in a very similar method to an ordinary titration. the only difference is in the context. Consider an unknown acid solution. Then a known amount of excess alkali was added to the solution and made them react. Then the process of finding the amount left from the alkali is known as the back titration.
Why is a back titration sometimes used for an analysis rather than a direct titration?
Back titrations are used when a reaction occurring in the conical flask can not be detected using an indicator such as phenolphthalein. So, after this titration has been performed, the 'excess' is then titrated with something that can be detected more easily using phenolphthalein etc.
How could you determine whether phenolphthalein remains in the residue of a titration reaction?
The easiest way is to add back some of the solution you were titrating. If phenolphthalein remains, it will react with the solution and change back to purple. Incidentally, phenolphthalein will always remain in the solution of the titration reaction - it changes color depending upon the pH of the solution, but the indicator itself is not affected by the titration reaction.
Is an alternative pH indicator practical for the back titration?
No.
When to use back-titration instead of direct titration?
When you have passed the tipping point and the color indicator turns from it's color to the clear color of the original solution. Then you back titrate to color again.
What are complexometric titration method?
Direct titration, Indirect titration, back titration, replacement titration and so on
What is Back titration?
A back titration is a form of titraiton in which an excess of standard reagent is added and then the reverse of the titration is carried out.
What is a back titration?
A back titration is a form of titraiton in which an excess of standard reagent is added and then the reverse of the titration is carried out.
When should back titration used instead of back titration?
when we do not know nothing about the other titrant.
How do you check the alcohol percentage in wine?
Using a method called back-titration, the alcohol concentration of a grape wine can be determined. Just google steps and procedure of back-titration and find out what standard solution and indicator you will need. :)
What difference between titration and back titration?
In fact, a back titration is carried out as in a very similar method to an ordinary titration. the only difference is in the context. Consider an unknown acid solution. Then a known amount of excess alkali was added to the solution and made them react. Then the process of finding the amount left from the alkali is known as the back titration.
What is the colour of phenolphthalein above pH equals 9?
Phenolphthalein is the PH indicator used to detect the acidity of the solution. When the solution is acidic or near-neutral (PH<8.2), it's colorless; when the solution is basic (8.2<PH<10.0),it will turn from colorless to pink, and gradually turns fuchsia when PH reaches 12.0, back to colorless when overpasses 12.0.
What are different types of EDTA titration?
1. Direct Titration In direct titration, you simply add an indicator to the solution of the metal ion and titrate with EDTA. Before starting the titration,it is needed to check that the pH of the solution to obtain a good formation constant value and on the other hand indicator colour change as well. 2.Indiract titration EDTA can be used as titrant for anions. Anions can be precipitated with suitable metal ion. Filter and wash the ppt with proper solution. Then boil in excess EDTA to complex metal ion(ppt). Back titrate to determine how much metal ion you had. 3.Back Titration In a back titration an excess of EDTA is added to the metal ion solution, and the excess EDTA is titrated with a known concentration of a second metal ion. The second metal ion must form a weaker complex with EDTA than the analyte ion so the second metal does not displace the analyte ion from its complex with EDTA. 4.Displacement titration Here the analyte is treated with an excess of a second metal bound to EDTA. The analyte ion displaces the second metal from the EDTA complex, and then the second metal is titrated with EDTA.
