Table of Contents
- 1 What indicator is used for a strong acid and strong base?
- 2 What indicator is used for a weak base?
- 3 Why can’t indicators be used for a weak acid weak base titration?
- 4 Which indicator is used for weak acid and weak base titration?
- 5 Why are indicators weak acids and bases?
- 6 Which indicator is used to find out the strength of an acid or base How?
- 7 Which indicator is used for the titration of weak acid and weak base Mcq?
- 8 Why is an indicator a weak acid?
- 9 Which indicator is best used in a titration?
- 10 What are the indicators used in titrations?
- 11 Which acid base indicator should be used?
What indicator is used for a strong acid and strong base?
phenolphthalein indicator
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.
What indicator is used for a weak base?
Substances such as phenolphthalein, which can be used to determine the pH of a solution, are called acid-base indicators. Acid-base indicators are either weak organic acids or weak organic bases. The anion of methyl orange, In−, is yellow, and the nonionized form, HIn, is red.
Which of the following indicator is suitable for titration of strong acid with weak base consider vertical line in the titration graph is from 4 to 6?
In the acid-base titration involving strong base and weak acid, methyl red can be used as an indicator.
Why can’t indicators be used for a weak acid weak base titration?
A solution of a weak acid cannot be titrated with a weak base using an indicator to find the end-point because the pH change is too gradual close to the equivalence point.
Which indicator is used for weak acid and weak base titration?
Choice of Indicators
| Types of titration | Indicators |
|---|---|
| Strong acid-strong base | Phenolphthalein is usually preferred because of its more easily seen colour change. |
| Weak acid-strong base | Phenolphthalein is used and change sharply at the equivalence point and would be a good choice. |
What is the best indicator for weak acid and weak base?
Choosing an appropriate indicator for a titration
| pH | 0 | Use |
|---|---|---|
| thymol blue (1st change) | < 1.2 | strong acid + weak base |
| bromophenol blue | < 3.0 | strong acid + weak base |
| methyl orange | < 3.1 | strong acid + weak base |
| bromocresol green | < 3.8 | strong acid + weak base |
Why are indicators weak acids and bases?
Acid – Base indicators (also known as pH indicators) are substances which change colour with pH. They are usually weak acids or bases, which when dissolved in water dissociate slightly and form ions. At low pH values the concentration of H3O+ is high and so the equilibrium position lies to the left.
Which indicator is used to find out the strength of an acid or base How?
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.
Which indicator is used for weak acid and weak base?
Phenolphthalein
Choice of Indicators
| Types of titration | Indicators |
|---|---|
| Strong acid-strong base | Phenolphthalein is usually preferred because of its more easily seen colour change. |
| Weak acid-strong base | Phenolphthalein is used and change sharply at the equivalence point and would be a good choice. |
Which indicator is used for the titration of weak acid and weak base Mcq?
END-POINT DETECTION :-
| Titration Between | pH at end point | Commonly used indicator |
|---|---|---|
| Weak acid and strong base | Alkaline range | Thymol Blue, Phenolphthalein |
| Weak base and strong acid | Acidic range | Methyl orange, Methyl red |
Why is an indicator a weak acid?
How do you choose an indicator?
When selecting an indicator for acid-base titrations, choose an indicator whose pH range falls within the pH change of the reaction. For example, in the titration of a strong acid with a strong base, the pH quickly changes from 3 to 11.
Which indicator is best used in a titration?
Choosing indicator for titrations Strong Acid v Strong Base. The diagram shows the pH curve between strong acid to a strong base, for methyl orange and phenolphthalein. Strong Acid v weak base. In this graph the indicator methyl orange is used and change color of end product from yellow to orange which is very close to equivalence Weak Acid v strong base. Weak acid v weak base.
What are the indicators used in titrations?
Indicators are substances that change colour when they are added to acidic or alkaline solutions
What makes a good indicator for titration?
In all cases, though, a good indicator must have the following properties: The color change must be easily detected. The color change must be rapid. The indicator molecule must not react with the substance being titrated. To minimize errors, the indicator should have a pKin that is within one pH unit of the expected pH at the equivalence point of the titration.
Which acid base indicator should be used?
Natural Dyes. This important acid-base indicator is produced from lichens. Lichens are differentiated into forms that grow on plants,and those that grow on soil and rocks.