iGCSE pH Indicators Quiz

What is the primary function of a pH indicator?

• To measure temperature

• To determine the acidity or alkalinity of a solution

• To measure the volume of a liquid

• To determine the density of a substance

Which of the following is a characteristic colour change of methyl orange in acidic solutions?

• Blue to green

• Red to yellow

• Yellow to red

• Green to blue

At what pH range does phenolphthalein change colour?

• 0-2

• 3-5

• 8-10

• 11-14

What colour does litmus paper turn in a basic solution?

• Red

• Blue

• Green

• Yellow

What is the pH of a neutral solution?

• 0

• 7

• 14

• 10

What colour does universal indicator show at a pH of 3?

• Red

• Yellow

• Green

• Orange

What is the colour of phenolphthalein in a basic solution?

• Colourless

• Pink

• Blue

• Red

What is the typical pH range for methyl orange?

• 0-3

• 3.1-4.4

• 4.5-6.0

• 6.1-7.5

What colour does litmus paper turn in an acidic solution?

• Red

• Blue

• Green

• Yellow

Which of the following is not a pH indicator?

• Methyl orange

• Phenolphthalein

• Sodium chloride

• Litmus