Discolouration

The video tutorial introduces the concepts of acidic and alkaline solutions, explaining their properties and how they can be identified using indicators like litmus reagent. An experiment is conducted using vinegar and baking soda to demonstrate color changes. The tutorial also covers natural indicators such as purple cabbage and discusses the historical discovery of litmus by Robert Boyle. The session concludes with a review and quiz to reinforce learning.

What is the symbol for hydrogen ions in an acidic solution?

• OH+

• OH-

• H+

• H-

Which of the following is true about alkaline solutions?

• They contain a large number of hydrogen ions.

• They are characterized by the presence of OH- ions.

• They turn red with litmus reagent.

• They taste sour.

What is the primary function of an acid-base indicator?

• To make a solution more acidic.

• To determine the color of a solution.

• To change the temperature of a solution.

• To indicate the acidity or alkalinity of a solution by changing color.

In the experiment, what color does the litmus reagent turn in a baking soda solution?

• Purple

• Green

• Blue

• Red

Which solution did not change color during the litmus test?

• Purified water

• Baking soda

• White vinegar

• Lemon juice

Which of the following is NOT a natural indicator for pH?

• Purple cabbage

• Carrots

• Salt

• Grapes

What color does phenolphthalein turn in an alkaline solution?

• Red

• Blue

• Colorless

• Green

Who discovered the earliest litmus reagent?

• Marie Curie

• Albert Einstein

• Isaac Newton

• Robert Boyle

Which of the following is an example of an acidic substance found in everyday life?

• Detergent

• Orange

• Soap

• Baking soda

Under normal conditions, what is the nature of human blood?

• Neutral

• Weakly alkaline

• Strongly alkaline

• Strongly acidic