Oxygen And Oxides Flashcards
How do you make oxygen in the lab
2H20(aq) –> 2H2O + O2 using a catalyst of manganese oxide
Percentages of the main gases present in the air
Nitrogen - 78.1%
Oxygen - 21.0%
Argon - 0.9%
Carbon dioxide - 0.04%
How do you test for oxyge
Oxygen relights a glowing splint
What happens when you burn magnesium
Burns with a bright white flame and gives a white powdery ash of magnesium oxide. The flame is extremely bright in pure oxygen.
What happens when you burn sulphur
Burns in the air with a tiny almost invisible blue flame. With oxygen it burns with a bright blue flame. A poisonous colour less sulphur dioxide gas is produced.
What happens when you burn carbon
When Carbon is heated it gives off a colour less carbon dioxide gas. The carbon may produce a small yellow-orange flame and perhaps some sparks.
What happens when you mix metal oxides with water
Most won’t react with water, but some react a bit and if you test the pH of the water it is slightly basic (alkaline)
What happens when you react non-metal oxides with water
They often react to form acidic solutions. Common exceptions are water and carbon monoxide
Why is rain slightly acidic
Because of the dissolved carbon dioxide. It’s even more acidic because of various pollutants.
How do you make carbon dioxide in the lab
Dilute hydrochloric acid and calcium carbonate in the form of marble chips.
How do you test for carbon dioxide
Lime water - turns milky white in the presence of carbon dioxide
What are the properties of carbon dioxide
Colourless and odourless gas
Denser than air
Slightly soluble in water
Uses of carbon dioxide
Fizzy drinks - dissolves in water under pressure
Fire extinguishers - denser than air
