Understanding pH Indicators

What is the primary function of pH indicators?

• To increase the acidity of a solution

• To measure temperature changes

• To change color based on hydrogen ion concentration

• To neutralize a solution

What happens when blue litmus paper is placed in an acidic solution?

• It dissolves

• It turns blue

• It turns red

• It remains unchanged

Which color does phenolphthalein turn in a basic solution?

• Yellow

• Clear

• Pink to purple

• Red

What is the key ingredient in red cabbage that acts as a pH indicator?

• Carotene

• Tannin

• Chlorophyll

• Anthocyanin

How can you make a red cabbage pH indicator at home?

• Boil red cabbage in water for 20 minutes

• Freeze red cabbage and then thaw it

• Mix red cabbage with vinegar

• Grind red cabbage into a powder

What pH level is indicated by a red cabbage solution turning pink?

• Around 7

• Around 2

• Around 9

• Around 14

What is the approximate pH of lemon juice as determined by the red cabbage indicator?

• 5

• 10

• 7

• 2

Which household substance tested with the red cabbage indicator has a pH of about 9?

• Baking soda

• Vinegar

• Ammonia

• Lemon juice

What safety equipment is recommended when making a red cabbage pH indicator?

• Ear plugs and a helmet

• Boots and a lab coat

• Safety glasses and an apron

• Gloves and a mask

What pH level does ammonia have when tested with the red cabbage indicator?

• 7

• 3

• 14

• 9