Podcast
Questions and Answers
What is the primary function of an indicator?
What is the primary function of an indicator?
What is the most common indicator used for testing acids and bases in the laboratory?
What is the most common indicator used for testing acids and bases in the laboratory?
What happens when an acid is added to blue litmus?
What happens when an acid is added to blue litmus?
What is the neutral colour of methyl orange?
What is the neutral colour of methyl orange?
Signup and view all the answers
What is the purpose of using litmus paper in the laboratory?
What is the purpose of using litmus paper in the laboratory?
Signup and view all the answers
What is the term for a water-soluble base?
What is the term for a water-soluble base?
Signup and view all the answers
What is the characteristic of litmus?
What is the characteristic of litmus?
Signup and view all the answers
What is the colour of methyl orange indicator in basic solution?
What is the colour of methyl orange indicator in basic solution?
Signup and view all the answers
What happens when a base is added to red litmus?
What happens when a base is added to red litmus?
Signup and view all the answers
What is the colour of phenolphthalein indicator in acid solution?
What is the colour of phenolphthalein indicator in acid solution?
Signup and view all the answers
What is litmus extracted from?
What is litmus extracted from?
Signup and view all the answers
What is the colour of litmus paper when it comes in contact with a basic solution?
What is the colour of litmus paper when it comes in contact with a basic solution?
Signup and view all the answers
What happens to the colour of turmeric when it comes in contact with a basic solution?
What happens to the colour of turmeric when it comes in contact with a basic solution?
Signup and view all the answers
Why does the yellow stain of curry on a white cloth turn reddish-brown when soap is scrubbed on it?
Why does the yellow stain of curry on a white cloth turn reddish-brown when soap is scrubbed on it?
Signup and view all the answers
What happens to the colour of the stain when the cloth is rinsed with plenty of water?
What happens to the colour of the stain when the cloth is rinsed with plenty of water?
Signup and view all the answers
What is the general term for substances like litmus and turmeric that change colour in response to changes in acidity or basicity?
What is the general term for substances like litmus and turmeric that change colour in response to changes in acidity or basicity?
Signup and view all the answers
Study Notes
Acid-Base Indicators
- An indicator is a substance that changes color when it comes into contact with an acid or a base, indicating whether the substance is acidic or basic.
- Litmus, Methyl Orange, and Phenolphthalein are three common indicators used to test for acids and bases.
Litmus Indicator
- Litmus can be used in the form of litmus solution or litmus paper.
- It has two types: Blue Litmus and Red Litmus.
- Acid turns Blue Litmus to Red, while a Base (or Alkali) turns Red Litmus to Blue.
- Litmus is a natural indicator with a neutral color of purple.
Methyl Orange Indicator
- Methyl Orange is a synthetic indicator with a neutral color of orange.
- It turns red in acid solution and yellow in basic solution.
Phenolphthalein Indicator
- Phenolphthalein is a synthetic indicator with a neutral color of colorless.
- It is colorless in acid solution and turns pink in basic solution.
Universal Indicator
- The universal indicator is another acid-base indicator that will be discussed later.
Natural Indicators
- Litmus is extracted from a type of plant called lichen, belonging to the division Thallophyta.
- Turmeric is also a natural indicator, containing a yellow dye that turns red in basic solutions.
- Turmeric is found in curry and can change color when coming into contact with soap solution, which is basic in nature.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Learn about indicators and how they change color to identify acids and bases. Discover the three most common indicators: Litmus, Methyl orange, and Phenolphthalein.
