(a) What is a universal indicator? For what purpose is it used?
(b) How does a universal indicator work?
(c) Water is a neutral substance. What colour will you get when you add a few drops of universal indicator to test-tube containing water?
(a) Universal indicator is a mixture of different indicators that gives different colours at different pH values. The scale ranges from 0 to 14. It gives an idea of how acidic or basic a substance is.
(b) Universal indicator is a pH indicator. It shows colour change to identify acid or base. It exhibits several colour changes according to the nature of the solution.
(c) Water is a neutral substance, pH=7, therefore, it shows a green colour.
Related Articles
- (a) What would you expect the pH of pure water to be?(b) What colour would the universal indicator show in an aqueous solution of sugar? Why?(c) A sample of rain water turned universal indicator paper yellow. What would you expect its pH to be? Is it a strong or a weak acid?
- What colour will universal indicator show if you add it to the following substances?(a) Potassium hydroxide, pH = 12 (b) Soda water, pH = 5(c) Sulphuric acid, pH = 2
- Explain the universal indicator.
- A beaker of concentrated hydrochloric acid has a pH of 1. What colour will full range universal indicator turn if it is added to this beaker? Is it a strong or a weak acid?
- Why water is called a universal solvent?
- Water is a universal solvent. Justify the statement.
- In an experiment to measure the pH values of solutions, a student placed strips of universal indicator paper in four beakers containing solutions A, B, C and D. The colour of universal indicator paper in these solutions is as shown below :The solution having lowest pH value is:(1) A(2) B(3) C(4)D"
- Here are some results of solutions tested with universal indicator paper:
- A student was given four unknown solutions in test-tubes marked A, B, C and D and asked to test them with universal indicator solution. He observed that on putting universal indicator solution, the solutions A, B, C and D turned blue, orange, green and red respectively. The test-tube which contains sodium chloride solution is :(1) A (2) B (3) C (4) D
- When a student added universal indicator solution to one of the following chemicals, its colour changed to navy blue. The chemical is most likely to be :
- Solution A turns universal indicator blue to purple whereas solution B turns universal indicator orange to red.(a) What will be the action of solution A on litmus? (b) What will be action of solution B on litmus? (c) Name any two substances which can give solutions like A. (d) Name any two substances which can give solutions like B. (e) What sort of reaction takes place when solution A reacts with solution B?
- What is an Indicator?
- (a) What effect does the concentration of H+ (aq) ions have on the nature of a solution?(b) What effect does the concentration of OH– ions have on the nature of a solution? (c) Someone put some universal indicator paper into vinegar. The pH is 3. What does this tell you about the vinegar? (d) Someone put some universal indicator paper onto wet soap. The pH is 8. What does this tell you about the soap? (e) State whether a solution is acidic, alkaline or neutral if its pH is :(i) 9 (ii) 4 (iii) 7 (iv) 1 (v) 10 (vi) 3
- (a) What is an indicator? Name three common indicators.(b) Name the acid-base indicator extracted from lichen. (c) What colour does the turmeric paper turn when put in an alkaline solution?
Kickstart Your Career
Get certified by completing the course
Get Started
Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
