Table of Contents
- 1 How would this experiment be different if you had forgotten to add the phenolphthalein?
- 2 What colour does phenolphthalein turn in Sulphuric acid?
- 3 What was the purpose of the phenolphthalein in this experiment?
- 4 What is the purpose of adding phenolphthalein to your Erlenmeyer flask prior to starting a titration?
- 5 Why is phenolphthalein used as an indicator in the titration?
- 6 What was the purpose of the phenolphthalein indicator in this experiment?
- 7 What indicator can be used instead of phenolphthalein?
- 8 What is the difference between phenolphthalein and bromocresol green?
- 9 What is the colour change of phenolphthalein?
- 10 What is the function of phenolphthalein in pH test?
How would this experiment be different if you had forgotten to add the phenolphthalein?
If we forgot to add the phenolphthalein to the Erlenmeyer flask, no chemical reaction or color change would occur. Therefore, there will not be a change in the pH in the solution and you will not know the equivalence point either. This is called the equivalence point.
What colour does phenolphthalein turn in Sulphuric acid?
pink
Because sulfuric acid is a strong acid and sodium hydroxide is a strong base, the phenolphthalein will turn pink because the solution has become more basic.
Why was phenolphthalein a good indicator to use for determining the equivalence point between the unknown weak acid and strong base?
A strong acid- strong base titration is performed using a phenolphthalein indicator. Phenolphtalein is chosen because it changes color in a pH range between 8.3 – 10. It will appear pink in basic solutions and clear in acidic solutions. Neutralization is the basis of titration.
What was the purpose of the phenolphthalein in this experiment?
In this experiment, a phenolphthalein color indicator will be used. Phenolphthalein is colorless in acidic solutions and pink in basic solutions. Phenolphthalein is also used in forensic crime scene analysis to detect the presence of blood, Kastle-Meyer test.
What is the purpose of adding phenolphthalein to your Erlenmeyer flask prior to starting a titration?
In the titration of acetic acid with aqueous NaOH, phenolphthalein is used as the indicator. Phenolphthalein is nearly colorless in acidic solution, but turns pink at a pH of about 8. This indicates that the base has neutralized all the acid.
How does phenolphthalein change color?
Furthermore, it turns pink when it comes in contact with a substance of a pH of 8.2 and becomes purple at an even higher pH. Moreover, this change in colour is a result of ionization; that alter the charge and shape of Phenolphthalein molecule.
Why is phenolphthalein used as an indicator in the titration?
Phenolphthalein is used as an indicator in acid-base titration as it indicates the change in pH by changing its colour [actually, going from colourless (in acidic solution) to pink colour(in basic solution)].
What was the purpose of the phenolphthalein indicator in this experiment?
What happens if you add too much phenolphthalein?
The intensity of the color is concentration dependent, so if a large amount of phenolphthalein is present the color could be very strong at the end-point. However, the presence of a large amount of phenolphthalein is not usually the reason a titration mixture has an intense color.
What indicator can be used instead of phenolphthalein?
However, it would make sense to titrate to the best possible colour with each indicator. If you use phenolphthalein, you would titrate until it just becomes colourless (at pH 8.3) because that is as close as you can get to the equivalence point….
| indicator | pKind |
|---|---|
| litmus | 6.5 |
| methyl orange | 3.7 |
| phenolphthalein | 9.3 |
What is the difference between phenolphthalein and bromocresol green?
In the case of bromocresol green if we end titration once the color change is complete we will be 0.0001 mL (0.1 μL) from the quivalence point, in the case of phenolphthalein if we end titration at first sight of the color change we are 0.0016 mL (1.6 μL) from the equivalence point.
Why is Bromophenol blue used instead of phenolphthalein in antacid titration?
For example, bromophenol blue shows a change in color in range between pH 3.0 to pH 4.6 and phenolphthalein shows a color change in range between pH 8.3 to pH 10. Hence, bromophenol blue is used as an indicator rather than phenolphthalein in antacid titration.
What is the colour change of phenolphthalein?
Phenolphthalein is naturally colourless and works differently then litmus paper. Also, it turns in pink colour in an alkaline solution or base. Moreover, the compound remains colourless in acids but starts to turn pink on pH 8.2 and continues to turn bright purple in strong bases. Colour Change of Phenolphthalein
What is the function of phenolphthalein in pH test?
Phenolphthalein People know the terms acid or base (acidic or alkaline) from common household things. But, the function of the pH indicator is far advanced. Furthermore one of the pH testers is Phenolphthalein, which is usually colourless but on coming in contact with aid or base changes its colour from pink (acidic) to purple (base).