What are acids?

• Acids are compounds that release hydroxide ions (OH-) when dissolved in water.

• Acids are chemical compounds that release hydrogen ions (H+) when dissolved in water.

• Acids are chemical compounds that release nitrogen ions when dissolved in water.

• Acids are substances that neutralize metals.

What are bases?

• Bases are substances that can donate protons.

• Bases are substances that can accept hydrogen ions (H+)

• Bases are substances that can donate pairs of hydrogen ions.

• Bases are substances that can accept electrons.

What is a universal indicator?

• A substance that changes color based on the pH of a solution.

• A type of chemical reaction involving combustion.

• A substance that changes color based on the temperature of a solution.

• A tool used to measure weight in chemistry experiments.

How does a universal indicator help in identifying the pH of a substance?

• Universal indicator helps in identifying the pH of a substance by tasting it.

• Universal indicator helps in identifying the pH of a substance by measuring the temperature.

• Universal indicator helps in identifying the pH of a substance by changing color based on the pH level of the substance.

• Universal indicator helps in identifying the pH of a substance by emitting a specific sound.

What happens during a neutralisation reaction?

• An acid reacts with a base to form acid and base.

• An acid reacts with a base to form salt and water.

• A base reacts with an acid to form salt and carbon dioxide.

• An acid reacts with a base to form gas and solid.

What is the pH range for neutral substances?

• 5

• 7

• 10

• 8

What color does a universal indicator turn in the presence of a strong acid (pH 0-3)?

• Yellow

• Blue

• Green

• Red

What color does a universal indicator turn in the presence of a strong base (pH 12-14)?

• green

• purple

• yellow

• red

What color does a universal indicator turn in the presence of a neutral substance?

• Yellow

• Green

• Red

• Blue

If a substance turns red when a universal indicator is added, what is its pH?

• 4-6

• 7-9

• 10-12

• 1-3