pH and indicators

What are indicators used for?

• To neutralize acidic or basic substances
• To measure the concentration of an acid
• To determine the color of a substance
• To indicate the acidity or basicity of a solution

What is the definition of pH?

• The measure of how acidic or basic a substance is
• The measure of how strong an acid or alkali is
• The measure of how much oxygen a substance contains
• The measure of how much hydrogen a substance contains

What color does universal indicator turn in neutral solutions?

• Red
• Yellow
• Green
• Blue

Which indicator is red in acidic solutions and yellow in neutral solutions?

• Methyl Orange
• Blue litmus paper
• Phenolphthalein
• Universal indicator

What does a pH level of <7 indicate?

• An acidic substance
• A basic substance
• A neutral substance
• A strong acid

What color does phenolphthalein turn in alkaline solutions?

• Purple
• Red
• Pink
• Colorless

What color does blue litmus paper turn in acidic solutions?

• Blue
• Red
• Green
• Yellow

What colour would universal indicator turn when added to soap?

• Dark green
• Purple
• Yellow
• Red

What colour would universal indicator turn when added to a solution of pH 5?

• Orange
• Green
• Red
• Blue

What would a pH of 8 indicate about a substance?

• Weak alkali
• Strong alkali
• Neutral
• Weak acid