How do you prepare phenolphthalein indicator for titration? Why is NaOH used in titration? Why is titration repeated three times? What makes a good indicator for titration? Why is HCl not used in titration? How
How does an acid-base indicator work (why does it change color at a certain pH)? What is the Ka of an indicator that changes color at a pH of 3.5? What is the range of a pH indicator? a. the pH values where the indicator will not react b. the range of pH values where ...
Add a drop or two of the Kastle-Meyer solution. This is aphenolphthaleinsolution, which should be colorless or pale yellow. If the solution is pink or if it turns pink when added to the swab, then the solution is old or oxidized and the test will not work. The swab should be uncolore...
Fruits were squeezed and the titratable acid content of the juice was measured by titration with 0.1 M sodium hydroxide and a phenolphthalein indicator. Juice total soluble sugar content was measured in Brix degrees using a table refractometer ATAGO PR-1. Brix and acidity were analyzed on the...
[16] Judy Doje points out that the phenolphthalein test will eventually turn pink in all cases since this is a catalytic reaction. That is why the reaction has to be evaluated immediately on application of the reagents in order to evaluate it as an indicator for the presence of blood. [17...
The color indi- cator phenolphthalein, which changes from colorless to pink between pH 8.2 and 10, was added to the saltwater (10 ml of a 1% solution). Phenolphthalein is insensitive to salinity effects. A similar approach was developed by de Vriendt (2021) to investigate the mixing zone. ...
Why we use phenolphthalein indicator in the determination of the strength of NaOH by using standard oxalic acid? Why not the others indicator? Explain the concept of analytical chemistry. Why should the funnel be removed from the top of the burette while the titration is...
Give the structure for an acid-base indicator. It can be any acid-base indicator, except phenolphthalein. Explain how an acid-base indicator works (why it changes color when it does). Give the chemical reaction(s) that shows why the color changes in your Explain the difference between an...
Describe how on a molecular level the indicator phenolphthalein works in different transitions. Explain why the appearance of the wood flame is yellow whereas the gas flame most often appears blue. Explain why benzoic acid do not affect litmus paper?
What is the function of the indicator phenolphthalein? How does the observed color intensity depend on solution concentration? Is the indicator typically added to the titrant or the analyte in a titration? Explain why. Define the term analyte in a titration. How to calculate the quencher contracti...