Why are different types of indicator required for different pH?
Acid and base indicators are used in chemistry to determine a substance’s pH. They change to different colors depending on whether they are added to an acid, a base or a neutral substance. Most indicators are themselves weak acids and respond to changes in the hydrogen ion concentration.
Why do we use different indicators?
To neutralize a strong acid with a weak base gives an acid salt and thus a pH on the acid side. Conversely a weak acid with a strong base gives an alkaline salt, so a pH on the alkaline side. Thus you may be instructed to use different indicators to give a colour change at the right point.
What are the different indicators used for titration reactions?
Indicator Range
| Indicator | Colour | |
|---|---|---|
| Bromocresol Green | yellow | blue |
| Methyl Red | yellow | red |
| Bromothymol Blue | yellow | blue |
| Phenol Red | yellow | red |
Why different indicators are used to identify the acids and alkalis?
When an acid is dissolved in water we get an acidic solution. When a base dissolves in water it is an alkali and makes an alkaline solution….Litmus.
| Red Litmus | Blue Litmus | |
|---|---|---|
| Acidic solution | Stays red | Turns red |
| Neutral solution | Stays red | Stays blue |
| Alkaline solution | Turns blue | Stays blue |
Why do indicators change colors at different pH levels?
The color change of a pH indicator is caused by the dissociation of the H+ ion from the indicator itself. Recall that pH indicators are not only natural dyes but also weak acids. The dissociation of the weak acid indicator causes the solution to change color.
When using pH indicators What is the most accurate method to use to find a specific pH?
To find the specific pH of a sample, you will need a pH test paper or strip that is more precise than a litmus strip. More precise pH test papers or strips can give test results down to 0.2 pH units.
What are three commonly used types of pH indicators in chemistry?
Some of the most widely-used pH testing tools are pH indicators, including phenolphthalein (range pH 8.2 to 10.0; colorless to pink), bromthymol blue (range pH 6.0 to 7.6; yellow to blue), and litmus (range pH 4.5 to 8.3; red to blue).
How does a pH indicator work?
pH indicators detect the presence of H+ and OH-. They do this by reacting with H+ and OH-: they are themselves weak acids and bases. If an indicator is a weak acid and is coloured and its conjugate base has a different colour, deprotonation causes a colour change.
How do you know what pH indicator to use?
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.
Do you know why we see different color of different solutions?
Objects appear different colours because they absorb some colours (wavelengths) and reflected or transmit other colours. The colours we see are the wavelengths that are reflected or transmitted. White objects appear white because they reflect all colours.
Why would you use more than one indicator to determine the pH of a solution?
Why would you use more than one indicator to determine the pH of a solution? Indicators generally change color over narrow ranges of pH.
Which pH indicator is the most accurate?
pH meters
pH meters are the most accurate type of measurement and are widely used.