C11 + C12 Reactivity And Dynamic Equilibrium Flashcards
What’s the reactivity series
A list of metals in order of reactivity and the lost reactive at the top
When are bubbles of has formed
The metals that react with dilute acids form hydrogen and a salt solution
Bubbles are formed and the more reactive the metal the more bubbles
The more easily metal atoms lose electrons ….
The higher the metal in the reactivity series
What are displacement reaction
Work only one way, the more reactive metal will react with the substance so the other less reactive metal is displaced
Displacement reactions are also…
Redox reactions
What are spectator ions
Thus do not change - they don’t lose or gain electrons so can be cancelled out In an ionic equation
What’s a redox reaction
A reaction when 1 substance Is oxidised and another is reduced
Where are very unreactive metals found
Found naturally in their native states (as in combined elements)
What’s extraction
The process of obtaining a metals a metal from these compounds such as rocks
What’s an ore
Is a rock that contains enough of a compound to extract a metal for profit
How can metal be extracted with displacement reaction
Use a carbon to displace the metal you want, heat it
USED FOR ELEMENTS BELOW CARBON IN THE REACTIVITY SERIES
How are metals extracted with electrolysis
Used for extracting metals above carbon on reactivity. Series
Involves passing electricity through a molten ionic compound to decompose it into its elements
A lot of energy is needed to keep metal oxides molten - so expensive
What’s bioleaching
Uses bacteria grown on a low-grade ore the bacteria produce a solution containing copper ions called a leachate, copper is extracted from the leachate by displacement using scrap iron, then purified by electrolysis this can be used for metals such as nickel, cobalt, zinc and copper
No high temps needed
Toxic substances can be produced
What’s phytoextraction
Involves growing plants that absorb metal compounds, which can be burnt to form an ash and then extract the metal
Very slow
Can extract metals from contaminated soils
What’s oxidation and reduction
Oxygen is the gain of oxygen by a substance
Reduction is the loss of oxygen from a substance
ALWAYS OCCUR TOGETHER - called redox reactions
When does corrosion happen
When a metal reacts with oxygen it will make the metal weaker over time
The metal is oxidised
What’s rusting
The corrosion of iron that requires water as well as oxygen
What’s a tarnish
Some metals from a protective oxide layer to prevent further rust
Tell me about reversible reactions
Show a double arrow to show forward and backward reactions occur at the same time
What’s dynamic equilibrium
Forward and backward reactions are still occurring but the percentages of the reactants and products are no longer changing
Reactions still occurring but remain in balance
When does dynamic equilibrium occur
Only occurs in closed systems - no loss of reactants or products
In an open system, gases could escape and so equilibrium could not be achieved
Tell me about the Haber process
Involves reversible reaction between nitrogen and hydrogen that can reach a dynamic equilibrium to make ammonia
Conditions chosen to favour the forward reaction and make as much for cheap
Conditions are a temp of 450 C and a pressure of 200 atmospheres
Use of iron catalyst
What happens to equilibrium when increasing temperature
In the endothermic direction, equilibrium shifts there
Where does the equilibrium position shift when decreasing temperature
In the exothermic direction
What happens to equilibriums position when increasing gas pressure
In the direction that forms Fewer gas molecules , as this reduces pressure
What happens to the equilibrium position when decreasing gas pressure
In the direction that forms more gas molecules
As this increased pressure
What happens when increasing or decreasing a concentration to the equilibrium position shifts
When increasing, In the direction that uses up the substance that has been added
When decreasing, in the direction that froms more of a substance that has been removed
What’s bad about electrical waste such as phones and toasters
They are made of precious metals so we need to recycle
Tell me some advantages of recycling metals
Natural reserves of metal ores will last longer
The need to mine ores is reduced so less noise and pollution created
Less pollution as less metals are extracted that forms sulfur dioxide when extracted
Many metals need less energy to recycle them than to extract new metal
Less waste metal means less landfill
Tell me disadvantages of recycling
Including coats and energy in collecting , transporting and sorting metals to be recycled - not economical
What’s a LCA
Life cycle assessment
What’s do LCAs do
Work out environmental impact of a product eg disposal, usage, manufacture and getting raw materials
Helps to decide if it’s worthwhile to manufacture and recycle a product - compare the effect of using different materials for the same products eg a bottle glass or plastic
