Acid-Base Indicators and pH

Monica introduces acid-base indicators, explaining their role in identifying the pH of solutions. She lists common indicators like methyl orange and bromothymol blue, describing their color changes in different pH environments. The video details how to use a pH chart to determine if a solution is acidic or basic, with examples provided for clarity. Monica concludes with practice assignments to reinforce understanding.

What is the primary function of acid-base indicators?

• To measure temperature changes in solutions

• To identify the pH of an acid or base solution

• To determine the concentration of a solution

• To calculate the molecular weight of compounds

Which of the following is NOT a listed acid-base indicator in the video?

• Universal indicator

• Bromothymol blue

• Phenolphthalein

• Methyl orange

What happens to the color of an acid-base indicator in an intermediate pH range?

• It remains unchanged

• It becomes colorless

• It shows a mixture of two colors

• It turns black

At a pH of 6.4, what color does bromothymol blue appear?

• Red

• Blue

• Yellow

• Green

What is the color of bromocresol green at a pH of 5.0?

• Purple

• Green

• Yellow

• Blue

If phenolphthalein is in a solution with a pH of 10, what color will it be?

• Colorless

• Blue

• Pink

• Yellow

What color does methyl orange turn at a pH of 6?

• Blue

• Yellow

• Red

• Green

At what pH does phenolphthalein start to turn pink?

• 7

• 8

• 9

• 10

What is the color of bromothymol blue in a solution with a pH of 2.0?

• Blue

• Red

• Yellow

• Green

What should students focus on to effectively use the pH indicator chart?

• Learning chemical equations

• Understanding the color change regions

• Calculating molecular weights

• Memorizing all pH values