Carbon dioxide and oxygen in atmosphere

Which substance is used as a catalyst in the reaction producing oxygen gas?

• Sodium chloride

• Manganese dioxide

• Copper sulfate

What gas is produced during the decomposition of hydrogen peroxide?

• Oxygen

• Nitrogen

• Carbon dioxide

What is the purpose of using a glowing splint in the experiment?

• To stir the solution

• To test for the presence of oxygen

• To add heat to the reaction

What happens to the glowing splint if oxygen is present?

• It changes color

• It relights or glows brighter

• It extinguishes

What is the main observation when hydrogen peroxide decomposes?

• Bubbles of oxygen gas

• Formation of a precipitate

• Temperature decrease

What is the appearance of manganese dioxide?

• White powder

• Black powder

• Green crystals

What is the purpose of blowing out the flame on the wooden splint before testing for oxygen?

• To ensure it is just glowing

• To prevent burning

• To cool it down

What happens if you blow a lime water?

• Lime water turns black

• Lime water produce fire

• Lime water turns milky / cloudy

What gas gives out when you blow the lime water and reacts with it?

• Carbon dioxide

• Oxygen

• Nitrogen

Which gas supports for respiration and combustion?

• Oxygen

• Carbon dioxide