What is the solution use in phenolphthalein test?
Phenolphthalein is often used as an indicator in acid–base titrations. For this application, it turns colorless in acidic solutions and pink in basic solutions. It belongs to the class of dyes known as phthalein dyes.
What color is phenolphthalein in basic solution?
Pink
The color of phenolphthalein in the basic medium is Pink. Phenolphthalein is often used as an indicator in acid-base titrations. For this application, it turns colorless in acidic solutions and pink in basic solutions.
Is phenolphthalein a base or acid?
weak organic acid
Phenolphthalein is a weak organic acid. Its undissociated molecule (HPh) is colourless while its ion (Ph−) is pink in colour. pH range of Phenolphthalein is 8−9.
Which solution will turn phenolphthalein pink?
The answer is NaOH or Sodium Hydroxide as it is a base.
How do you make an indicator solution?
- Add 5 g to 500 mL of ethanol, add 500 mL water. Stir.
- Dissolve 1 g of phenolphthalein powder in 500 mL of 50% alcohol. Add drops of this phenolphthalein solution to 100 mL of 0.5 mol / litre sodium hydroxide solution until a deep pink colour appears.
- Add colourless phenolphthalein indicator to lime water.
What color is phenolphthalein in acidic solution?
colorless
Phenolphthalein remains colorless in acidic solution but turns pink in the basic solution. Phenolphthalein undergoes a color change according to the pH of the solution.
Why does phenolphthalein turn pink in a base?
Ionization and the Phenolphthalein Indicator If hydrogen ions (H+, as found in an acid) were added to the pink solution, the equilibrium would switch, and the solution would be colorless. Adding hydroxide ions (OH-, as found in bases) will change the phenolphthalein into its ion and turn the solution pink.
What colour is phenolphthalein in acid?
Colourless
Other indicators
| Indicator | Acidic | Alkaline |
|---|---|---|
| Methyl orange | Red | Yellow |
| Phenolphthalein | Colourless | Pink |
What is the pH of phenolphthalein?
phenolphthalein, (C20H14O4), an organic compound of the phthalein family that is widely employed as an acid-base indicator. As an indicator of a solution’s pH, phenolphthalein is colourless below pH 8.5 and attains a pink to deep red hue above pH 9.0.
What is the pH level of phenolphthalein?
8.2 – 10.0
Indicator Range
| Indicator | Colour | pH range |
|---|---|---|
| Bromothymol Blue | yellow | 6.0 – 7.6 |
| Phenol Red | yellow | 6.8 – 8.4 |
| Thymol Blue – 2nd change | yellow | 8.0 – 9.6 |
| Phenolphthalein | colourless | 8.2 – 10.0 |