Metals and the Reactivity Series Flashcards
What is reduction
When a substance looses oxygen
What is galvanising
The process of coating Iron with Zinc
What s sacrificial protection
The process of attaching a more reactive metal to Iron, thereby preventing rusting. Oxygen reacts with the more reactive metal rather than Iron.
What is Metallic Bonding
The electrostatic attraction between positive metal ions and delocalised electrons
metal + oxygen =
Metal Oxide
What is a reducing agent
A substance that reduces something else
What is an oxidising agent
A substance that oxidises something else
What are the advantages and disadvantages of using Iron for pipes
Strong
Easily malleable
Cheap
Iron will react with water = rust
Harder to shop than others
What are the advantages and disadvantages of using Lead for pipes
Malleable
Un-reactive
Poisonenes substance
What are the advantages and disadvantages of using Copper for pipes
Won’t react with water
Malleable
Expensive
What are the advantages and disadvantages of using Plastic for pipes
Cheap
Malleable
Un-reactive
Plastics (thermosetting) can’t be recycled
Lower melting point
More likely to break
Give 3 ways of preventing rust
Galvanising
Painting
Greasing it
When galvanising, if the zinc is damaged, why will the iron still not rust
Because the zinc is more active than the iron
Oxygen would rather react with the zinc instead of the iron
Zinc looses electrons more easily than iron, so used for sacrificial protection
What is a method to measure the % of oxygen in the air
Add copper to a tube which has gas syringes coming out of either end
Heat the copper with a bunsen burner
Keep moving the air across the copper by constantly pressing each end of the gas syringes
Before reading, stop heating for a little bit as when the air is hot, it expand so suggesting a lower percentage of oxygen than normal.
Reheat + measure until constant volume
What percentage of oxygen is in the air
20%
What is ‘dry air’
Air with no moisture so the water is hated and then evaporated into dry air
Give some properties of metals
Shiny
Malleable / Ductile
Conducts heat
Conducts electricity
Describe what happens when metal atoms bond together to form the solid metal
The outer electrons on each atom become free to move throughout the whole structure. The electrons become delocalised
The metal atoms are held together by the strong electrostatic attraction between the positive metal ions and delocalised negative electrons. This is metallic bonding.
Metals tend to be……with high……………….and………………… because of the…….electrostatic forces between the positive ions and delocalised electrons
Strong
Melting Points
Boiling Points
Strong
Why do metals conduct electricity
Because of the delocalised electrons that can move
Why are metals dense
Particles packed as close together as possible
Why are metals malleable
Layers of atoms which can slide over each other
Why are alloys less malleable
The layers can’t slide over each other as easily as before
