Redox, Rusting and Iron Flashcards
(35 cards)
What three things can oxidation be defined as?
-Gain of oxygen
-Loss of hydrogen
-Loss of electrons
What three things can reduction be defined as?
-Loss of oxygen
-Gain of hydrogen
-Gain of electrons
What is a redox reaction?
A redox reaction is a reaction where both reduction and oxidation occur at the same time.
What two conditions are needed for rusting to occur?
Oxygen and water.
What is the fancy name for rust? What is the symbol equation?
Hydrated iron (III) oxide. (Fe2O3.xH2O).
What are the four barrier methods used to prevent rusting?
-Painting
-Oiling
-Plastic coating
-Metal plating
What needs to be done in order for metal plating to work properly?
The iron must be fully covered with a thin layer of metal.
Give some examples of when the barrier method ‘painting’ would be used?
Ships, railings and car bodies.
Give some examples of when the barrier method ‘oiling’ would be used?
Moving machinery parts, bike chains and gate hinges.
Give some examples of when the barrier method ‘plastic coating’ would be used?
Paper clips, fridge shelves and gym weights.
What is galvanising? Where would it be used?
When the iron is completely plated with zinc. Garden tools, buckets and chains.
What are food cans made from iron covered with to prevent rusting?
Tin!
What are ‘shiny’ bath taps made from iron covered with to prevent rusting?
Chromium.
In some cases, why might barrier methods not be used to reduce rusting? Where might this be the case?
If they are not suitable or are too expensive. With massive structures such as oil rigs and the hulls of ships made from steel.
How would oil rigs be prevented from rusting? Why is this done?
By placing zinc blocks on to the steel. Zinc is more reactive than iron and so it reacts with water and oxygen first.
What is sacrificial protection?
A metal that is more reactive than iron reacts in preference to the iron, so the iron does not rust.
How are the hulls of ships and petrol storage tanks protected form rusting?
Magnesium blocks are placed on to them.
If iron is the only metal that rusts, what happens to the other metals?
They corrode.
What’s is another name for limestone and what is the symbol equation?
Calcium carbonate. (CaCo3).
What is the main ore of iron and what does it contain?
Haematite and it contains iron (III) oxide (Fe2O3).
In the iron ore, how is the iron extracted?
In a blast furnace.
What does coke contain?
Carbon (C).
Why is iron a cheap metal?
Because the ore is abundant.
Why is iron used in many structures and bridges?
Because of its strength.
