Day 15 Indicators '25 Answer Key

At what pH would all three indicators appear as yellow?

• 1.9

• 2.9

• 4.7

• 8.7

In which solution will thymol blue indicator appear blue?

• 0.1 M CH₃COOH

• 0.1 M KOH

• 0.1 M HCl

• 0.1 M H₂SO₄

Which indicator is yellow in a solution with a pH of 9.8?

• methyl orange

• bromthymol blue

• bromcresol green

• thymol blue

Which indicator is blue in a solution that has a pH of 5.6?

• bromcresol green

• bromthymol blue

• methyl orange

• thymol blue

Which indicator would best distinguish between a solution with a pH of 3.5 and a solution with a pH of 5.5

• bromthymol blue

• bromcresol green

• litmus

• thymol blue

Three samples of the same solution are tested, each with a different indicator. All three indicators, bromthymol blue, bromcresol green and thymol blue, appear blue if the pH of the solution is

• 4.7

• 6.0

• 7.8

• 9.9

What is the color of the indicator thymol blue in a solution that has a pH of 11?

• red

• blue

• pink

• yellow

An indicator was used to test a water solution with a pH of 12. Which indicator color would be observed?

• colorless with litmus

• red with litmus

• colorless with phenolphthalein

• pink with phenolphthalein

When tested, a solution turns red litmus to blue. This indicates that the solution contains more

• H⁺ than OH⁻ ions

• H₃O⁺ ions than OH⁻ ions

• OH⁻ ions than H₃O⁺ ions

• H⁺ and OH⁻ ions than H₂O molecules

In a solution, litmus is blue. The pH of the solution could be

• 10

• 2

• 3

• 4