What is universal indicator solution used for?
A universal indicator is a pH indicator made of a solution of several compounds that exhibits several smooth colour changes over a wide range of pH values to indicate the acidity or alkalinity of the solution. They are used to indicate the acidity and alkalinity of the solution by colour change.
What is pH paper used for?
pH paper is used to determine if a solution is acidic, basic or neutral. This is determined, by dipping part of the pH paper into a solution of interest, and watching the colour change.
Who invented phenolphthalein?
Adolf von Baeyer
Phenolphthalein, which is closely related to the triphenylmethane dyes, was discovered in 1871 by the German chemist Adolf von Baeyer, who prepared it by fusing phenol and phthalic anhydride in the presence of sulfuric acid or zinc chloride, the procedure still employed.
What is the pH value of universal indicator?
Universal indicator
| pH range | Description | Colour |
|---|---|---|
| 3–6 | Weak acid | Orange or Yellow |
| 7 | Neutral | Green |
| 8–11 | Weak alkali | Blue |
| > 11 | Strong alkali | Indigo or Violet |
What is the pH range of universal indicator?
Universal indicator and the pH scale This is measured using the pH scale , which runs from pH 0 to pH 14. Universal indicator has many different colour changes, from red for strongly acidic solutions to dark purple for strongly alkaline solutions. In the middle, neutral pH 7 is indicated by green.
What colour is pH paper?
Litmus paper is usually more reliable, and comes as red litmus paper and blue litmus paper. The table shows the colour changes it can make….Litmus.
| Red litmus | Blue litmus | |
|---|---|---|
| Acidic solution | Stays red | Turns red |
| Neutral solution | Stays red | Stays blue |
| Alkaline solution | Turns blue | Stays blue |
What is the pH of red cabbage?
2
Red Cabbage pH Indicator Colors
| pH | 2 | 10 |
|---|---|---|
| Color | Red | Blue-Green |