C4 Extracting metals and Equilibria

Question 1

Where are metals found and in what form?

Answer 1

• extracted from ores
• in earth crust
• unreactive metals are found as combined elements

Question 2

metal + acid –> ??

Answer 2

metal salt + hydrogen

Question 3

metal + water –> ??

Answer 3

metal hydroxide + hydrogen

Question 4

How can we deduce reactivity of a metal when reacted with water?

Answer 4

metal + H2O –> metalOH + H

• hyrogen gas produced in form of bubble
• the more bubbles the more reactive

Question 5

What is the reduction and oxidisation? (with oxygen)

Answer 5

reduction
-loss of oxygen

oxidisation
-gain of oxygen

Question 6

How does the reactivity series affect the relative resistance to oxidisation?

Answer 6

a less reactive metal will not displace a more reactive metal from a metal salt so relatively oxidation will or will not occur

Question 7

Which metals are more reactive than carbon?

Answer 7

• potassium
• sodium
• calcium
• magnesium
• aluminium

Question 8

Which metals are more reactive than hydrogen?

Answer 8

• potassium
• sodium
• calcium
• magnesium
• aluminium
• zinc
• iron
• lead

Question 9

Which metals are less reactive than carbon?

Answer 9

• zinc
• iron
• lead
• copper
• silver
• gold
• platinum

Question 10

Which metals are less reactive than hydrogen?

Answer 10

• copper
• silver
• gold
• platinum

Question 11

Which metals are unreactive with water?

Answer 11

• lead
• copper
• silver
• gold
• platinum

Question 12

What are displacement reactions? (electrons)

Answer 12

• more reactive metal replace less reactive metal from a metal salt
• redox reaction
• gain and loss of electrons (oilrig)

Question 13

What are the two most common methods of metal extraction?

Answer 13

• burning metal ores with carbon

- electrolysis

Question 14

Why does a metals position in the reactivity series determine what extraction process to use?

Answer 14

-burning with carbon
–displacement reaction
—if metal is more reactive than carbon displacement will not occur so no metals are extracted

electrolysis used for metals more reactive than carbon and not others since it is expensive

Question 15

Which metals can be extracted from metal ores by being burnt with carbon?

Answer 15

zinc
iron
tin
lead
copper
silver
gold
platinum

Question 16

Which metals must be extracted from metal ores by electrolysis?

Answer 16

potassium
sodium
calcium
magnesium 
aluminium

Question 17

How useful are biological methods of metal extraction? 2 examples

Answer 17

phytoextraction
bioleaching

advantages:

• reduce need for mining
• conserves high grade ores
• allows use of low grade ores
• can be used to decontaminate ground
• reduces rock waste from mining
• preserves natural habitats
  (b) -doesnt require high temp

disadvantages:

• very slow process
  (p) - requires high temperatures
  (p) - CO2 produced when plants are burned which is a green house gas
  (b) - produces toxic substances eg sulfuric acid which damage environment

Question 18

What are the environmental benefits of recycling? (metals)

Answer 18

-less mines
–reduces deforestation 
–reduces noise and dust pollution 
-reduced waste sent to landfill
–saves valuable space
-conservation of raw material
-conservation of fossil fuels
-less energy required to recycle than to mine 
-reduces greenhouse gas emissions from consumption of fossil fuels to mine

Question 19

What are the economic benefits of recycling?

Answer 19

-recycling requires less energy than mining
–reduced energy cost
-recycled metals and materials are cheaper to buy than raw materials
-recycling is an industry
–jobs
–economic growth

Question 20

What factors do you need to consider when evaluating each stage of the life cycle assessment of a product?

Answer 20

• energy required
• amount of water needed
• amount if resources used
• waste produced (in all forms)
• waste disposal
• impact on environment of all above points