What are indicators?
2. What are the different types of indicators? Write with examples
3. Write any 2 properties of Acids
4. Write any 2 properties of Bases.
5. rite the examples of strong acids and weak acids
6. Write the examples of strong bases and weak bases
7. Define concentrated acid
8. Define dilute acid
9. What is Alkali? Give example.
10. What is Olfactory indicator?
Answers
Explanation:
1. The substance that changes colour in acid and base are called indicator.
2. There are different types of indicator:
* China Rose juice - It turns green in a basic medium & magenta in acidic medium.
*Litmus paper - It changes blue to red in acidic medium & red to blue in basic medium.
*Phenolphthalein - It remains colourless in acidic medium and it changes colourless to pink in basic medium.
*Methyl orange - It changes orange to pink in acidic medium and orange to yellow in basic medium.
*Red cabbage juice - It changes purple to red in acidic medium and purple to green in basic medium.
3. Properties of acid are :
* Acids are sour in taste.
*Acids conduct electricity.
4. Properties of base are :
* Bases are bitter in taste.
* Bases feels slippery ( soapy ) when felt between fingers.
5. Examples of Strong acid are : Hydrochloric acid, Sulphuric acid, Nitric acid ,etc.
Examples of weak acid are : Ascorbic acid, Citric acid , Acetic acid ,etc.
6. Examples of strong base are: Sodium Hydroxide, Calcium Hydroxide, Ammonium Hydroxide,etc.
Examples of weak base are: Magnesium Hydroxide, Aluminum Hydroxide,etc.
7. Acid which contains low percentage of water is said to be concentrated acid.
8. Acid which contains high percentage of water is said to be dilute acid.
9. Bases which are soluble in water are called alkalis. Example : Sodium Hydroxide, Potassium Hydroxide,etc.