pH Indicator Experiment Analysis

The video tutorial demonstrates how to use red cabbage as a pH indicator to test acidity and basicity. The experiment involves preparing indicator solutions and observing color changes when breathing into them before and after exercise. The science behind the experiment is explained, focusing on how carbon dioxide from respiration forms carbonic acid, affecting the solution's pH. The tutorial also covers how chemical indicators like phenolphthalein work and how to create a homemade indicator using red cabbage.

What is the expected color change when vinegar is added to the red cabbage indicator?

• Pink

• Green

• Yellow

• Blue

How much water is used to dilute the indicator in each glass during preparation?

• One cup

• Half a cup

• A quarter cup

• Two cups

What is the purpose of breathing into the indicator solution before exercise?

• To measure the acidity of the solution

• To observe color change without exercise

• To test the effect of temperature

• To test the effect of oxygen

What color is the indicator solution immediately after exercise?

• Green

• Clear

• Yellow

• Red cabbage color

What is the significance of the color change observed five minutes after exercise?

• It indicates a decrease in CO2 levels

• It indicates an increase in oxygen levels

• It shows the solution is becoming more acidic

• It suggests the solution is returning to its original state

What is the main product of cellular respiration that affects the indicator solution?

• Oxygen

• Carbon dioxide

• Nitrogen

• Hydrogen

What chemical reaction occurs when carbon dioxide is combined with water?

• Formation of sulfuric acid

• Formation of carbonic acid

• Formation of nitric acid

• Formation of hydrochloric acid

What is the role of phenolphthalein in the experiment?

• To neutralize the solution

• To increase acidity

• To act as a base

• To change color based on pH

What happens to the solution when a base is added to neutralize the carbonic acid?

• It turns blue

• It remains clear

• It turns pink

• It turns yellow

What is the purpose of using red cabbage in the experiment?

• To provide a natural pH indicator

• To act as a food source

• To increase the acidity of the solution

• To act as a preservative