Phenolphthalein changes from colorless to red in the range of pH = 8.0 to 9.6
The indicator should change color right at the equivalence point, so 5.
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.
The color does not change unless an indicator such as litmus or phenolphthalein is being used. If litmus the color change is blue to red If phenolphthalein the change is red to colorless
If phenolphthalein is added to a solution of salts, it will not undergo any specific reaction. Phenolphthalein is used as an indicator in acid-base titrations, where it changes color depending on the pH of the solution. Since salts do not have acidic or basic properties, phenolphthalein will not exhibit any color change.
When using an indicator in a titration, the color changes happen when the titrant has reacted with all the substance of interest in the sample. As soon as the titrant isn't reacting with the sample any more, it starts reacting with the indicator, and continuing past the first hint of color will be using too much titrant, and the calculations for the concentration of the sample will be wrong. Phenolphthalein starts out pink, but will turn red as the pH keeps changing as you go further past the endpoint of the titration.
The indicator should change color right at the equivalence point, so 5.
hc20h1354
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.
when the equivalence point of a titration is achieved.. Added: (More precisely:) The equivalence point is the point where the number of moles of base equal the number of moles of acid. The end point is the point where the indicator being used changes color (also 'indication point)'. If the indicator is chosen correctly, the end point will essentially be exactly as near as possible at the equivalence point. The point of the titration is to find the equivalence point -- the end point is just a very close approximation to it. This is because the pH of the solution changes very rapidly close to the equivalence point. Therefore, the indicator will change color very close to the equivalence point because of the steepness of the pH change
Titration without indicator is only possible with another measurement:Examples / possibilities:pH-electrode measurement (acid-base titration)Conductivity measurement (acid-base titration or ion-reaction)Change of color by excess or depletion of the reactant/titrant (redox titration)Precipitation by excess or depletion of the reactant/titrantAdded:(The following was more or less written for 'indicator' titrations, but same principles count for other 'sharply' changing properties):The equivalence point is the point where the number of moles of titrant equal the number of moles of the reactant. The end point is the point where the indicator being used changes color (also 'indication point)'.If the indicator is chosen correctly, the end point will essentially be as near as possible at the equivalence point.The point of the titration is to find the equivalence point -- the end point is just a very close approximation to it. This is because the pH of the solution changes very rapidly close to the equivalence point.Therefore, the indicator will change color very close to the equivalence point because of the steepness of the pH change
The equivalence point is the point where the number of moles of base equal the number of moles of acid. The end point is the point where the indicator being used changes color (also 'indication point)'. If the indicator is chosen correctly, the end point will essentially be exactly as near as possible at the equivalence point. The point of the titration is to find the equivalence point -- the end point is just a very close approximation to it. This is because the pH of the solution changes very rapidly close to the equivalence point. Therefore, the indicator will change color very close to the equivalence point because of the steepness of the pH change.
The color does not change unless an indicator such as litmus or phenolphthalein is being used. If litmus the color change is blue to red If phenolphthalein the change is red to colorless
No, phenolphthalein remains colourless in the presence of an acid.
Phenolphthalein itself is a chemical. It changing color is a chemical change.
Titration in which the end point is marked by a color change.
Yes, the color become pink.
Litmus paper or phenolphthalein.