Seperate Chemistry (1) Qs Flashcards
What are the typical properties of transition metals?
High melting point/ High density/ For coloured compounds/ can be used as catalysts
Which transiton 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 it is oxidised; oxygen gains electrons so it is reduced
What is rusting?
The corrosion of iron when it reacts to oxygen and water in the air
What two products need to be excluded to prevent rusting?
Oxygen and Water
How can oxygen and water be excluded to prevent iron rusting?
Paint the metal; Coat the metal in oil; cover the metal in plastic; keep the metal in a vaccum container
What is sacrificial protection?
When the metal being protected from rusting is more galvanized with a more reactive metal
How does sacrificial protection prevent corrosion?
The outer metal corrodes first and will prevent the corrosion of the inner metal
What metal is used for the sacrificial protection of iron?
Zinc
What is electroplating?
A procces in which a metal is coated with a layer of another metal
State two reasons for using electroplating
To make the metal more resistant to corrosion; To improve the appearance of a metal (eg silver plated cutlery)
