Explosive Chemistry Demonstrations

What is the primary reason for maintaining safety during chemistry demonstrations?

• To prevent boredom

• To avoid accidents and injuries

• To ensure accurate results

• To impress the audience

What is the main product formed when methane undergoes combustion?

• Carbon dioxide

• Carbon monoxide

• Methanol

• Hydrogen gas

Why is cornstarch used in the fire-breathing demonstration?

• It has a high carbon content and surface area

• It is non-flammable

• It is a liquid fuel

• It is easy to ignite

What prevents cornstarch from exploding in everyday settings?

• It is mixed with water

• It is always wet

• It is stored in airtight containers

• Oxygen cannot penetrate a pile of cornstarch

What role does a catalyst play in a chemical reaction?

• It increases the temperature

• It provides energy to the reactants

• It changes the products of the reaction

• It speeds up the reaction by lowering activation energy

What is the purpose of adding dish soap in the catalyst demonstration?

• To change the color of the reaction

• To trap the oxygen gas released

• To increase the temperature

• To neutralize the reaction

What is the temperature of liquid nitrogen used in the phase change demonstration?

• 77 Kelvin

• 273 Kelvin

• 0 Kelvin

• 100 Kelvin

What happens to nitrogen molecules during the phase change demonstration?

• They change into a different element

• They move closer together

• They become solid

• They move further apart

Why is it important to wear cryogenic gloves during the liquid nitrogen demonstration?

• To prevent chemical burns

• To handle hot objects

• To protect hands from extreme cold

• To look stylish

What is the visual effect observed when hot water is added to liquid nitrogen?

• A large explosion

• Color change

• A bright flash of light

• Rapid boiling and vapor cloud