4) Extracting Metals & Equilibria

Question 1

What is the oxidation and reduction acronym?

Answer 1

OIL RIG

Question 2

What does an oxidation reaction involve?

Answer 2

Gaining oxyxgen

Losing electrons

Question 3

What happens when a metal reacts with oxygen?

Answer 3

Metal oxides are produced

Magnesium + oxygen –> magnesium oxide

Question 4

What does a reduction reaction involve?

Answer 4

Losing oxygen

Gaining electrongs

Question 5

What happens when metal oxides lose oxygen?

Answer 5

They return to their atomic form

Iron oxide + carbon monoxide –> iron + carbon dioxide

Question 6

What type of ion do metal atoms always form?

Answer 6

Positive cations

Question 7

What do we call very unreactive metals such as gold and platinum?

Answer 7

Native metals

Question 8

What is the reactivity of a metal linked to?

Answer 8

How easy it is to form its positive ion

Question 9

What happens in a displacement reaction?

Answer 9

A more reactive metal displaces a less reactive metal from a compound

Question 10

What is an example of a redox reaction?

Answer 10

Displacement

Question 11

WHat happens in metal displacement reactions?

Answer 11

More reactive metal is oxidised

Less reactive metal is reduced

Question 12

What do we call ions that do not change in reactions?

Answer 12

Spectator ions

Question 13

What type of reaction has added electrons in the products?

Answer 13

Reduction

Question 14

What type of reaction has added electrons in the reactants?

Answer 14

Oxidation

Question 15

What happens when the alkali metals react with water?

Answer 15

A metal hydroxide and hydrogen gas is produced

Question 16

What happens when potassium reacts with water?

Answer 16

Ignites instantly

Sparking and burning with lilac flame

Question 17

What happens when sodium reacts with water?

Answer 17

Fizzes rapidly and melts to form a ball that moves on water’s surface

Question 18

What happens when lithium reacts with water?

Answer 18

Fizzes steadily and floats, becoming smaller until it disappears

Question 19

How does reactivity change for the alkali metals?

Answer 19

Reactivity increases up the group

Question 20

What metals don’t react with dilute acids?

Answer 20

Copper
Silver
Gold
Platinum

Question 21

What does most metals react with dilute acids to form?

Answer 21

Salt

Hydrogen gas

Question 22

Why is carbon used to extarct metals?

Answer 22

High on reactivity series

Cheap and abundant

Question 23

How is carbon used to extract metals?

Answer 23

In the reduction, metal oxide loses oxygen to form a pure metal
Usually metal oxide is heated in presence of carbon uusally in coal form

Question 24

What 5 metals react with dilute acids but not water?

Answer 24

Magnesium
Aluminium
Zinc
Iron
Lead

Question 25

What is phytomining?

Answer 25

Extracting copper from contaminated land

Question 26

What is the process of phytomining?

Answer 26

1) Plants growing on contaminated land absorb copper ions | 2) These plants are harvetsed and burned producing ash containing high concentrations of copper compounds

Question 27

What is a disadvantage of phytomining?

Answer 27

Takes longer than other methods

Question 28

What is the process of bioleaching?

Answer 28

1) Bacteria are added to low-grade ores 2) Bacteria breaks down ores creatinga solution rich in copper compounds (leachate solution), we can easily extract copper from leachate solution

Question 29

WHat is a disadvantage of bioleaching?

Answer 29

Slower than traditional mining

Question 30

What does the process of recycling metals involve?

Answer 30

Melting metals before reshaping them

Question 31

Why is recycling metals preferable to mining and extracting new resources?

Answer 31

Less energy required Reduced burning of fossil fuels Conserves finite resources Fewer waste rock heaps

Question 32

What do LCAs assess?

Answer 32

All 4 stages of a product's life cycle to calcualte its environmental costs

Question 33

What does LCA stand for?

Answer 33

Life Cycle Assessment

Question 34

What are thhe 4 stages of a product's lifecycle?

Answer 34

1) Collecting raw materials needed 2) Making and packaging product 3) Product use 4) Disposal of product

Question 35

What are reversible reactions?

Answer 35

When the reactants and products can combine each way

Question 36

What is endo and exothermic reaction's relation to reversible reactions?

Answer 36

If the forward reaction is exothermic, the backwards reaction will be endothermic

Question 37

How much energy is relseased compared to energy absorbed in reversible reactions?

Answer 37

Energy relseased is exaclty equal to energy absorbed

Question 38

What is an example of a reversible reaction?

Answer 38

The Haber process

Question 39

What is formed in the Haber process?

Answer 39

Ammonia through the reaction of nitrogen and hydrogen

Question 40

What temperature and pressure if the Haber process carried out at?

Answer 40

450 degrees C with a pressure of 200 atmospheres

Question 41

When does a dynamic equilibrium occur?

Answer 41

When reversible reactions happen within a closed system

Question 42

What is a closed system?

Answer 42

A system where reactants and products can not be added or removed

Question 43

How does reaction rate and concentration of products and reactants change in a dynamic equilibrium?

Answer 43

Equal reaction rate | Concentrations of reactants and products do not change

Question 44

What do the conditions of a reversible reaction deermine?

Answer 44

The relative quantities of the different reactants and products in a reaction at equilibrium

Question 45

What does Le Chatelier's principle state?

Answer 45

If any of the conditions of a reversible reaction at equilibrium change, the closed system will counteract whatever has changed

Question 46

What is Le Chatelier's principle used to predict?

Answer 46

The outcome of any changes imposed on a system at equilibrium

Question 47

What does a decrease in temperature cause in equilibrium?

Answer 47

The position of equilibrium will shift in the exothermic direction

Question 48

How does a decrease in temperature affect the amount of products and reactants generated?

Answer 48

Products generated by exothermic reaction increases | Products generated by endothermic reaction decreases

Question 49

What does an increase in temperature cause in equilibrium?

Answer 49

The position of equilibrium will shift in the endothermic direction

Question 50

How does an increase in temperature affect the amount of products and reactants generated?

Answer 50

Products generated by endothermic reaction increases | Products generated by exothermic reaction decreases

Question 51

How does an increase in pressure affect the position of equilibrium?

Answer 51

Position shifts to favour reaction producing fewest gas molecules

Question 52

How does a decrease in pressure affect the position of equilibrium?

Answer 52

Position shifts to favour reaction producing most gas molecules

Question 53

What must be assessed to predict the outcome of a pressure change?

Answer 53

Balanced equations to see how many gas molecules are one ach side of the equation

Question 54

How does an increase in concentration of a reactant in equilibrium shift the position?

Answer 54

Forward reaction is favoured | Equilibrium position shifts towards products

Question 55

How does an increase in concentration of a product in equilibrium shift the position?

Answer 55

Backwards reaction is favoured | Equilibrium position shifts towards reactants