Indicators
Indicators: Overview
This topic provides information about indicators and explains how they change colours according to the pH alteration. We will learn in detail the behaviour of indicators. It also briefs on the properties of indicators and characteristics of a good indicator.
Important Questions on Indicators
Complete the following table:
| Indicator | Solution | Colour |
| Litmus | Lemon juice | |
| Litmus | Ammonium hydroxide | |
| Phenolphthalein | Ammonium hydroxide | |
| Phenolphthalein | Hydrochloric acid | |
| Turmeric juice | Soap solution | |
| Turmeric juice | Orange juice | |
| Red-cabbage juice | Soap solution | |
| Red-cabbage juice | Hydrochloric acid |
Red cabbage indicator turns red in _____ solutions.
Red cabbage indicator turns red to green when added to _____ solution.
The colour of red cabbage indicator in acidic solution:
A yellow stain of curry on a white cloth turns reddish brown when it comes in contact with soap. Why does it happen?
Which of the following substances are known to be the neutral substances?
Which of the following sources are used to extract the natural indicator - litmus?
The special type of substances used to test whether a substance is acidic or basic are known as _____.
When a strip of red litmus paper is dipped in the solution A, it remained red.
What is the possible nature of the solution A?
Solutions of substances that show a different colour in acidic, basic and neutral solutions are called as _____.
Which of the following substances act as the natural indicators?
What are indicators? Name any two indicators. Explain the effect of these indicators on acids and bases?
Indicators are substances which show change in colour when brought in contact with acid and bases.
Name one indicator which turns red on adding a base.
What is an indicator? Give two examples along with their action in acids and bases.
In an experiment, phenolphthalein was added to caustic soda. What will happen if diluted hydrochloric acid is added to this mixture. Explain.
The indicator that turns green in a basic solution _____.
