Metals 🎸 Flashcards
What are the products when a metal reacts with cold water?
Metal hydroxide and hydrogen gas.
What are the products when a metal reacts with steam?
Metal oxide and hydrogen gas.
What are the products when a metal reacts with dilute acids?
Salt and hydrogen
Why can a displacement reaction be called a redox reaction? Explain in terms of electron transfer.
A redox reaction occurs when reduction and oxidation are taking place in the same reaction.
In a displacement reaction, the more reactive metal atoms lose electron to form ions (oxidation) and the less reactive metal ions gain electron to form the element (reduction).
Where are metals extracted from?
Form ores found in the earths crust.
What is an ore?
A rack which contains metals often chemically combined with other substances.
Which metals are found in the earths crust as uncombined elements?
Unreactive elements
Explain what oxidation means in terms of oxygen.
Gain of oxygen
Explains what reduction means in terms of oxygen.
Loss of oxygen
How can metals be extracted from their ores?
Reduction with carbon: can only be done if metal is less reactive than carbon.
Electrolysis: Can be done with all metals, but requires a large amount of energy (high cost).
What are the typical properties of transition metals?
- High melting point
- High density
- Form coloured compounds
- Transition metals and their compounds can be used as catalysts
Which transition metal is used as a catalyst in the Haber process?
Iron
What causes metals to corrode?
Oxygen reacts with the metal to form a metal oxide,
Why is corrosion of a metal a redox reaction?
The metal loses electrons so is oxidised.
Oxygen gains electrons so is reduced.
What is rusting?
Rusting is the name specifically given to the corrosion of iron when it reacts to oxygen and water in the air.
What two substances need to be excluded to prevent rusting?
Oxygen (O2)
Water (H20)
How can oxygen and water be excluded to prevent iron rusting?
- Paint the metal
- Coat the metal in oil/grease
- Cover the metal in plastic
- Keep the metal in a vacuum container
What is sacrificial protection? How does it prevent corrosion?
Sacrificial protection is when the metal being protected from rusting is galvanised with a more reactive metal.
The outer metal will corrode first and will prevent the corrosion of the inner metal.
What is an alloy?
An alloy is a mixture of two or more metals or a metal and another element.
A pure metal can be converted into an alloy. How does this increase the strength of the product?
Alloys contain several metals which will have different sized atoms. This distorts the regular arrangement of the atoms so the layers are unable to slide over one another very easily.
