Air Flashcards
Air consists of the elements
Nitrogen (78%), oxygen (21%), argon (<1%), and the compounds carbon dioxide (0.03%) and water vapor (0-4%).
Air is a mixture because
It’s composition varies from place to place and the different gases condense as liquids at different temperatures.
Cobalt chloride papers
Used to test for the presence of water. It is blue when dry, pink when wet.
Limewater is used to
test for carbon dioxide. Carbon dioxide turns limewater milky.
Oxygen is prepared
By the breakdown of hydrogen peroxide (H2O2) into oxygen and water in the presence of manganese dioxide (MnO2).
Manganese dioxide is a catalyst
It speeds up the breakdown of the hydrogen peroxide.
A glowing splint
Used to test for oxygen. Oxygen relight a glowing splint.
Carbon dioxide is prepared by
The reaction between dilute hydrochloric acid (HC1) and marble chips (calcium carbonate (CaCO3).
Oxygen is used for
Breathing, welding and burning
Carbon dioxide is used in
Photosynthesis, fire extinguishers and fizzy drinks