Why does thymol turn blue?
Thymol blue (thymolsulfonephthalein) is a brownish-green or reddish-brown crystalline powder that is used as a pH indicator. It is insoluble in water but soluble in alcohol and dilute alkali solutions. It transitions from red to yellow at pH 1.2–2.8 and from yellow to blue at pH 8.0–9.6.
At what pH does thymol blue turn blue?
9.6 pH
Changes from red at 1.2 pH to yellow at 2.8 pH. Changes from yellow at 8.0 pH to blue at 9.6 pH.
How does thymol blue work as an indicator?
Thymol blue (TB) is an acid-base indicator from the family of the sulfonphthalein. An aqueous solution of TB undergoes the color changes from red to yellow in an acid solution (pKa ≈ 1.6) and from yellow to blue in an alkaline solution (pKa ≈ 8.9).
What color is thymol blue at a pH of 4?
| Indicator | pH Range | color in base form |
|---|---|---|
| Thymol Blue | 1.2 – 2.8 | yellow |
| Methyl Orange | 3.1 – 4.4 | orange |
| Methyl Red | 4.2 – 6.3 | yellow |
| Thymol Blue | 8.0 – 9.6 | blue |
What colour is thymol blue in acid?
red
| Indicator | pH Range | color in acid form |
|---|---|---|
| Thymol Blue | 1.2 – 2.8 | red |
| Methyl Orange | 3.1 – 4.4 | red |
| Methyl Red | 4.2 – 6.3 | red |
| Thymol Blue | 8.0 – 9.6 | yellow |
How do you make thymol blue indicator?
Thymol Blue Indicator Solution: Dissolve 0.1 g of thymol blue in 2.15 ml of 0.1 M sodium hydroxide and 20 ml of ethanol (95 percent). After the solution is effected, add sufficient water to produce 100 ml.
What pH is thymol blue when yellow?
pH 8.0–9.6
Thymol blue (thymolsulfonephthalein) is a brownish-green or reddish-brown crystalline powder that is used as a pH indicator. It is insoluble in water but soluble in alcohol and dilute alkali solutions. It transitions from red to yellow at pH 1.2–2.8 and from yellow to blue at pH 8.0–9.6.
What is the color of thymol blue indicator?
| Indicator | pH Range | color in acid form |
|---|---|---|
| Thymol Blue | 1.2 – 2.8 | red |
| Methyl Orange | 3.1 – 4.4 | red |
| Methyl Red | 4.2 – 6.3 | red |
| Thymol Blue | 8.0 – 9.6 | yellow |
Is thymol blue the same as Bromothymol blue?
As a pH indicator, bromothymol blue, for example, would be useful between from about pH 6.0 to pH 7.6….
| Indicator | Thymol blue (second transition) |
|---|---|
| Low pH color | yellow |
| Transition pH range | 8.0–9.6 |
| High pH color | blue |
How do you make a thymol blue indicator solution?
What can I use instead of bromothymol blue?
If bromothymol blue is inhibitory or not sensitive enough to detect small pH changes, substitute with phenol red (0.01g/l).
What is the color of the indicator thymol blue in a solution that has a pH of 11?
| Indicator | Low pH color | Transition pH range |
|---|---|---|
| Gentian violet (Methyl violet 10B) | yellow | 0.0–2.0 |
| Leucomalachite green (first transition) | yellow | 0.0–2.0 |
| Leucomalachite green (second transition) | green | 11.6–14 |
| Thymol blue (first transition) | red | 1.2–2.8 |
Why does thymol blue change color with pH?
Why does thymol blue change color at the pH that it does? Why does thymol blue change color at the pH that it does? Acid-base indicators are a substance which changes colour with pH. They are usually weak acids or bases and dissociate slightly to form ions.
What is thymol blue in infobox?
Infobox references. #N#. Chemical compound. Thymol blue (thymolsulfonephthalein) is a brownish-green or reddish-brown crystalline powder that is used as a pH indicator. It is insoluble in water but soluble in alcohol and dilute alkali solutions. Thymol blue ( pH indicator) below pH 8.0. #N#above pH 9.6. 8.0.
What is the difference between alizarine yellow and thymol blue indicator?
If the base strength is off the scale, i.e., a pH of > 13.5, and the acid has a pH > 5.5, an Alizarine yellow indicator may be used. On the other hand, if the acid is off the scale, i.e., a pH < 0.5, and the base has a pH < 8.5, a Thymol Blue indicator may be used.
What is the wavelength of thymol blue?
In other words, Thymol blue is an indicator. It transitions from red to yellow at pH 1.2–2.8 and from yellow to blue at pH 8.0–9.6. It is usually a component of Universal indicator. At wavelength (378 – 382) nm, extinction coefficient > 8000 and at wavelength (298 – 302) nm, the extinction coefficient > 12000.