extracting metals and equilibria

Question 1

What is oxidation?

Answer 1

Oxidation means the reaction with or addition of oxygen

Question 2

What is reduction in oxygen?

Answer 2

Reduction can be the removal of oxygen

Question 3

what is the reactivity series?

Answer 3

A reactivity series is a table that lists metals in order of their reactivity

Question 4

List the reactivity series

Answer 4

potassium
Sodium
Calcium
Magnesium
Aluminium
Carbon
Zinc
Iron
Hydrogen
Copper
Silver
Gold

Question 5

as you go down the list over the reactivity series what happens?

Answer 5

The less reactive they become, and more resistant to oxidation

Question 6

Why are the metals at the top of the series most reactive?

Answer 6

The metals at the top of the reactivity series are the most reactive – they easily lose their electrons to form cations (positive ions). They are also oxidise easily.

Question 7

Why are the metals at the bottom of the reactivity series less reactive?

Answer 7

this is because they don’t give up their electrons to form cations easily, and they are more resistant to oxidation than metals higher up than them.

Question 8

how can metals react with acids to tell you about their reactivity?

Answer 8

You can place little pieces of various metals into dilute hydrochloric acid
The more reactive the metal is the faster the reaction with the acid will go
Very reactive metals will fizz vigourously

Question 9

how can you show that hydrogen is forming during the reaction?

Answer 9

Burning splint test, the loud, the squeaky pop, the more hydrogen has been made in the period and the more reactive the metal is

Question 10

How can reactions of metal with water should the reactivity of metals?

Answer 10

Metals + water ——-> metal hydroxide + hydrogen
very reactive metals like potassium, sodium, lithium and calcium will all react vigourously with water, whereas less reactive metals like magnesium and iron won’t react that much with cold water but they will still react with steam
want to react at all

Question 11

what are displacement reactions?

Answer 11

Displacement reactions is where a more reactive element takes the place of a less reactive element in a compound

Question 12

What happens during a metal displacement reaction?

Answer 12

The more reactive metal loses electrons and the less reactive metal gains electrons
Surgery, displacement reaction the more reactive metal is oxidised and the less reactive is reduced
Ca+ ZnSO4——> CaSo4 + Zn

Question 13

what is a metal or and what is it used for?

Answer 13

A metal or is a rock which contains enough metal to make it economically worthwhile extracting the metal from it and many cases that or is an oxide of the metal
Most ores are in the Earth crust .Some unreactive metals, such as gold and platinum are present in the earths crust as uncombined elements. These metals are mine straight out from the ground, but they are usually refined before they can be used.

Question 14

How can some metals be extracted by the reduction with carbon?

Answer 14

metals higher than carbon in the reactivity series, have been extracted using electrolysis, which is expensive
Metals below carbon in the reactivity series can be extracted by reduction using carbon example, iron oxide is reduced in a blast furnace to make iron
This is because carbon can only take the oxygen away from the metals, which are less reactive than carbon itself

Question 15

What are the biological methods to extract metals?

Answer 15

Bioleaching: this uses bacteria to separate metals from the or e.g. copper can be separated from copper sulphate this way. The bacteria gets energy from the bond between the atoms in the ore separating out the metals from the or in the process. The leachate ( the solution produced by the process) contains metal ions, which can be extracted by electrolysis or displacement with a more reactive metal
phytoextraction: this involves growing plants in soil that contains metal compounds. The plants can’t use to get rid of the metals, so they gradually build up in the leaves. The metals can be harvested, dried and burnt in the surface – contains metal compounds of which the metals can be extracted by electrolysis or displacement reaction
But these methods are mining, are pretty damaging to the environment

Question 16

How does extracting metals also impact the environment?

Answer 16

mines are damaging to the environment and destroy habitats – not to mention the fact that they are a bit of an iso recycling. More metals means that we don’t need so many mines

Question 17

how does recycling materials, save energy

Answer 17

Recycling materials, save energy as this process often only uses a small fraction of the energy needed to extract and refine the material from scratch

Question 18

How does recycling have an important economic benefit?

Answer 18

extracting metals often requires more energy than just recycling. Them and energy does not come cheap. So recycling saves money.
Recycling is also a massive industry and creates lots of jobs

Question 19

what is the life-cycle assessment?

Answer 19

The life cycle assessment looks at each stage of the life of a product – from making the material from natural raw materials to making the product from the material, using the product and disposing of the product. It works out the potential environmental impact of each stage. It shows the total environmental costs.

Question 20

How can the choice of materials impact the environment?

Answer 20

metals have to be mined and extracted from the ores. These processes, need lots of energy and cause a lot of pollution.
Raw materials for chemical manufacturers. Often come from crude oil, crude oil is a nonrenewable source and supplies are decreasing. Also obtaining crude oil from the ground is refining into useful raw materials requires a lot of energy and generates pollution.

Question 21

How can manufacturing impact the environment?

Answer 21

manufacturing products uses a lot of energy and other resources
It can cause lots of pollution

Question 22

How can the product usage impact the environment?

Answer 22

using the product can also damage the environment for example
Paint gives off toxic fumes
Burning fuels releases, greenhouse, gases and other harmful substances
Fertilisers can leach into streams, and rivers caused damage to ecosystems

Question 23

How can disposal impact the environment?

Answer 23

Products are often disposed of in a landfill site
This takes up space and can pollute land and water
Products might incinerate(burn) which causes pollution(air)

Question 24

what are reversible reactions?

Answer 24

A reversible reaction is one where the products can react with other to produce the original reactants. In other words, it can go both ways.

Question 25

what is the haber process?

Answer 25

during the haber process, nitrogen and hydrogen react to form ammonia
The nitrogen is obtained easily from the air which is 78% nitro
The hydrogen can be extracted from hydrocarbons from sources, such as natural gas and crude oil
the haber process is carried out at 450°C with a pressure off 200 atm and an iron catalyst

Question 26

What is an equilibrium?

Answer 26

As the reactants react their concentrations for so the forward reaction will slow down as more and more of the products are made and their concentration rise. The backward reaction will speed up
After awhile, the forward reaction will be going at exactly the same rate as the backward one – equilibrium

Question 27

What is a dynamic equilibrium?

Answer 27

The forward and backward reactions are both happening at the same time at the same rate. The concentration of the reactants and products have reached abundant and won’t change.

Question 28

Where do equilibrium reversible reactions take place?

Answer 28

Equilibrium can only be reached if the reversible reaction takes place in the closed system a close system just means that none of the reactants or products can escape

Question 29

What are the three things that can change the position of equilibrium?

Answer 29

temperature
Pressure( for equilibrium involving gases)
Concentration ( reactants, or products)

Question 30

What happens to the equilibrium if you decrease or increase the temperature

Answer 30

If you decrease the temperature The equilibrium will move in the exothermic direction to produce more heat
If you increase the temperature, the equilibrium will move to the endothermic direction to absorb the extra heat

Question 31

what happens to the equilibria involving gases changes

Answer 31

if you increase the pressure, the equilibrium will move towards the side that has a few molecules of gas to reduce pressure
If you decrease the pressure, the equilibrium will move towards the side that has more molecules of gas to increase pressure

Question 32

What happens to the equilibria if you change the concentration

Answer 32

if you increase the concentration of the reactants, the equilibrium will move to the right to use up the reactants, making more products. the concentration of the product, the equilibrium will move to the left and use up the products
Decreasing the concentration will have the opposite effect

Question 33

How can you predict how the position of the equilibrium will change?

Answer 33

You can apply the rules of temperature pressure and concentration to any reversible reaction to work out how changing the conditions will affect the equilibrium positions and determine how right shift or left shift it would go
(towards or not towards the product)