Reactions Of Metals With Oxygen Flashcards
What does it mean if there is a triangle over the chemical reaction arrow in a chemical equation?
Applying heat
What two types of results can you get?
Qualitative
Quantitative
What are qualitative results?
Results that use the five senses, i.e. What does it look like
What are quantitative results?
Results that use numbers
What three things can you do to prevent corrosion?
Painting/greasing/oiling
Electroplating
Galvanising
What will happen to a metal left in the presence of Oxygen?
It will form a metal oxide through a chemical reaction
What colour is copper oxide that occurs naturally?
Green
What colour is copper oxide that forms in the presence of heat?
Black
What flame occurs in the combustion of copper?
Green
What does iron oxide look like when it reacts naturally?
Reddish brown flakes called rust
What does iron oxide look like when it combusts?
Dark grey
What is the oxide formed between Iron and Oxygen react with heat?
Magnetite
What is the chemical formula for rust?
Fe2O3
What colour is magnesium oxide?
White ash
What is the reaction of magnesium oxide like?
Bright white flash
Rapid reaction
What two metals are unlikely to react with oxygen?
Gold
Silver
What protects fruit from an oxygen attack?
Their skin/peel
What speeds up the rusting process? (Catalyst)
Water
Why is rusting a bad thing?
It weakens iron and steel, which are used as supports for buildings, cars etc.
What way can the rusting process be sped up even more?
Impurities (like salt) can be mixed in the water being used as the catalyst
Why are metals like aluminium and chromium being used more often?
They are not damaged by oxygen attacks.
How are aluminium and chromium protected?
The oxides of these metals form a layer (patina) around the metal, protecting the rest of the metal from the Oxygen
What three methods can be used to protect iron from rusting?
Painting/greasing/oiling
Electroplating
Galvanising
What is electroplating?
A negative current is sent through a plate of iron. The charged plate is then dipped into a bath of aluminium/chromium/ gold etc. These metals are attracted to the negatively charged iron, and so they coat the iron.
What is galvanising?
When an iron plate is dipped into a bath of zinc
Why does galvanising work?
Zinc oxide will form an extra layer around the zinc and zinc oxide, protecting both metals
What colour is copper naturally?
Orange
What flame is produced during the reaction between iron and oxygen in the presence of heat?
Orange sparks
What is a patina?
A layer of metal oxide that forms on the metal
What happens to water when it boils?
Oxygen gas is evaporated
The water is less likely to cause lots of rust
What compound absorbs moisture?
Calcium chloride
