C2 Flashcards
(98 cards)
1
Q
What is the chemical name and symbol for salt?
A
- Sodium Chloride
* NaCl
2
Q
Where is salt extracted from?
A
Large underground deposits left from millions of years ago, where seas once evaporated.
3
Q
What is rock salt a mixture of?
A
Rock salt contains sodium chloride and other impurities.
4
Q
How is rock salt brought to the ground?
A
Hot water is pumped underground which causes the salt to dissolve in the water. The water is the pushed to the surface under the pressure of water. This is called solution mining.
5
Q
What must be done after salt is extracted from an area?
A
Any holes left in the ground must be properly filled in to prevent the land from subsiding and collapsing into the holes.
6
Q
What is the earth made of?
A
Crust, lithosphere, mantle and core.
7
Q
What is the crust made of?
A
Solid rock.
8
Q
What does the lithosphere include?
A
The crust and upper part of the mantle, made up of a jigsaw structure.
9
Q
What happens as you go deeper into the mantle?
A
The temperature increases.
10
Q
What is a use for rock salt in its raw state?
A
It can be used as road salt.
11
Q
What products are made during the electrolysis of brine?
A
- Hydrogen
- Chlorine
- Sodium Hydroxide
12
Q
What is the chemical name for brine?
A
Sodium Chloride Solution.
13
Q
What type of material are the electrodes made out off?
A
The electrodes are made of an inert material. Meaning it does not react with with the products or reactants.
14
Q
At what electrode is hydrogen produced?
A
Hydrogen is made at the cathode.
15
Q
At what electrode is chlorine gas produced?
A
Chlorine gas is produced at the anode.
16
Q
How is sodium hydroxide formed during electrolysis?
A
Sodium hydroxide is made from the left over ions.
17
Q
What does radioactive decay create a lot of inside the earth?
A
Heat.
18
Q
What do tectonic plates do?
A
They float on the mantle.
19
Q
How fast do the plates move?
A
About 2.5cm per year.
20
Q
What can tell us what’s below the crust?
A
The seismic waves.
21
Q
Why do scientists use seismic waves?
A
To study the earth’s structure.
22
Q
what industry carries out the electrolysis of brine?
A
The Chlor-alkali industry.
23
Q
Who created the theory about the plates moving?
A
Alfred Wegener in 1914.
24
Q
Why was Wegener’s theory not accepted?
A
There was no real convincing evidence.
25
What is the name of the ridge that runs the whole length of the Atlantic?
The Mid-Atlantic ridge.
26
What was the evidence that suggested the sea floor was spreading and confirmed Wegener's theory?
Magma rises up through the sea floor, solidifies and forms underwater mountains that are roughly symmetrical.
27
How are volcanoes formed?
Volcanoes are formed when magma from the mantle emerges through the Earth's crust.
28
When is molten rock called magma and when is it called lava?
It is magma when it is below the surface of the earth and lava when it erupts from the volcano.
29
What else can cause volcanoes?
The oceanic and continental crust colliding.
30
How does the oceanic and continental crust colliding cause volcanoes?
- The crust at the ocean floor is denser than the crust below the continents.
- When they collide, the dense oceanic plate will be forced under, called subduction.
- As the oceanic crust is forced down, it melts and starts to rise. If the molten rock finds a way to the surface , volcanoes form.
31
How is igneous rock made?
Made when any sort of molten rock cools down and solidifies. The type depends on how quickly the molten rock has cooled.
32
How do scientists try to predict volcanic eruptions?
They study things like magma movement below or near to the volcano.
33
What are the three steps in the forming of sedimentary rock?
- Layers of sediment laid down in lakes or seas.
- Pressure squeezing out the water.
- Fluids flow through the pores and deposit natural mineral cement.
34
What is limestone made of?
Calcium carbonate.
35
What is the word and symbol equation for the thermal decomposition of limestone into carbon dioxide and calcium oxide?
calcium carbonate --> calcium oxide + carbon dioxide
| CaCO3 --> CaO + CO2
36
How are metamorphic rocks formed?
Metamorphic rocks are formed by the action of heat and pressure on sedimentary (or even igneous) rocks over long periods of time.
37
What do igneous rocks contain?
Different minerals in randomly arranged interlocking crystals.
38
What are ores?
Ores are minerals that can contain useful materials. For example aluminium and iron are extracted from their ores and are used in construction.
39
How is glass made?
Glass is made by melting limestone (calcium carbonate), sand (silicon dioxide) and soda (sodium carbonate).
40
How are bricks made and what from?
Bricks are made from clay. It is molded into bricks due to being soft when dug up. It is hardened by firing it at very high temperatures.
41
How is cement made?
Cement is made by heating up limestone and clay. Powdered clay and limestone are roasted in a rotating kiln to make a complex mixture of calcium and aluminium silicates, called cement.
42
How does extracting rocks cause environmental damage?
Quarrying uses up land and destroys habitats, it also costs money to make them look nice again once finished with. Things like transporting rock can cause noise and pollution.
43
What process is used to obtain very pure copper?
Electrolysis.
44
How is very pure copper obtained using electrolysis?
The impure copper is emerged in a liquid called the electrolyte which conducts electricity. The solution used is called copper (II) sulfate. The electrical supply pulls electrons off the copper atoms at the anode, causing them to go into the solution as Cu2+ ions. It then offers electrons at the cathode to turn the ions back into copper atoms. The impurities are dropped at the anode as a sludge whilst the pure copper atoms bond to the cathode.
45
What type of reaction occurs at the cathode?
A reduction (the gain of electrons).
46
What type of reaction occurs at the anode?
An oxidation (the loss of electrons).
47
What does recycling copper save?
Money and resources.
48
What is an alloy?
A mixture of a metal and other elements.
49
What properties do alloys often have?
The properties of the different metals/non-metals in it.
50
What is the alloy of iron and carbon?
Steel.
51
Why is steel more useful than iron?
It is stronger and harder than iron as well as being a lot less likely to rust in comparison to iron.
52
What is the name of a family of alloys of nickel and titanium that are 'smart'?
Nitinol, they are able to remember their original shape as they have shape memory.
53
What is another word for the corrosion of iron?
Rust.
54
What does iron need to be in contact with to rust?
Water and oxygen from the air.
55
What type of reaction occurs when iron rusts?
An oxidation reaction (it gains oxygen).
56
What is the word equation for the corrosion of iron?
iron + oxygen --> hydrated iron(III) oxide
57
What makes iron rust a lot faster?
Salty or acidic water.
58
Why does aluminium not corrode when wet?
Despite being made of iron, it is more reactive and so quickly forms a layer of aluminium oxide on the outside stopping any further reaction from taking place.
59
What are the advantages of aluminium over steel for car bodies?
It has a lower density so the body will be lighter. It will also corrode less than steel.
60
What are the disadvantages of aluminium over steel for car bodies?
It costs a lot more to make a whole body out of aluminium.
61
What are the different materials used to build a car?
- Steel (bodywork)
- Aluminium (parts of the engine)
- Glass (windscreen and windows)
- Plastics (interior trim)
- Fibres (seat and floor covers).
62
How much of the car has to be recycled by European law?
85%.
63
What is the biggest problem with recycling a car?
All the non-metal parts as they have to be separated and sorted out.
64
What are the five costs involved with production?
1) Energy Cost
2) Raw Materials Cost
3) Labour Cost
4) Plant Cost
5) Rate of production.
65
What type of conditions give the lowest cost during production?
The Optimal Conditions.
66
What does the phrase 'optimal conditions' mean?
The optimal conditions are those which give the lowest cost / Kg of product. Regardless of the rate of the reaction.
67
What type of reaction is the Haber process?
The Haber Process is a reversible reaction?
68
What is a reversible reaction?
A reaction in which the product can be turned back into the reactants.
69
Where is nitrogen obtained from during the Haber process?
Nitrogen is easily obtained from the surrounding air as 78% of the air is nitrogen.
70
Where is hydrogen obtained from during the Haber process?
Hydrogen is obtained from cracking hydrocarbons or from natural gas.
71
Why does all the nitrogen and hydrogen not convert into ammonia?
Because the reaction is reversible.
72
What has to be taken into account when reacting substances in a reversible reaction?
The conditions which are used, as a different pressure or temperature, might favor the forward or backward reaction, so depending on what the reactants and products are different conditions would be needed.
73
Why is 450 degrees used as the optimal temperature for the Haber process?
Because in the Haber process a high temperature favors the reverse reaction, meaning anything higher would start to turn too much ammonia back into the reactants, reducing the percentage yield. 450 degrees is a compromise between a decent yield and reaction time.
74
Who created the Haber Process?
Fritz Haber
75
How is nothing or very little wasted during the Haber Process?
Because any unused hydrogen and nitrogen are recycled.
76
Why is an iron catalyst used in the Haber Process?
The catalyst speeds up the rate of the foward reaction without helping the reverse reaction. Allowing the yield to stay the same but with a faster rate.
77
What would be the implications of not using a catalyst during the Haber process?
To get a good enough rate the temperature would need to be further increased, causing the yield to drop further.
78
Where is ammonium nitrate mainly used?
Ammonium Nitrate is mainly used in the production of fertilizers.
79
What method is used to create ammonium nitrate inside a lab?
The Titration Method.
80
What are the three steps to create ammonium nitrate using the titration method?
1) Setup the burette in a clamp stand which contains nitric acid above a flask which contains ammonia solution and an indicator.
2) Slowly add the acid into the flask taking note of colour change to the indicator so you can tell when the alkali has been neutralized.
3) Then to get ammonium nitrate crystals allow the solution to evaporate, and then let it crystallise.
81
In a titration why aren't the ammonium nitrate crystals not 100% pure, and how could this be resolved?
They may still contain some of the indicator solution, so the titration would need to be carefully repeated using the same volume of acid as before but with no indicator solution.
82
What is the purpose of using a fertilizer?
To provide plants with all the correct minerals for growth and repair.
83
What are the three main components of a fertilizer?
* Nitrogen
* Phosphorus
* Potassium
84
Why must fertilizers be soluble in water?
Because they need to be dissolved into a liquid (normally water) before being absorbed by the plants roots.
85
What process is used to create fertilizers?
Titrations involving ammonia.
86
What is the main issue with using fertilizers? (Especially near water sources)
Eutrophication can occur.
87
What is Eutrophication, and why is it a problem?
Eutrophication is when fertilizer runs off into rivers and streams. This causes levels of nitrates and phosphates in the water to increase. This causes algae living in the water to rapidly multiply resulting in an algae bloom. This algae bloom then causes light to be blocked from reaching organisms at the bottom of the water source causing plants to die. Aerobic bacteria then start to feed on the dead plants and rapidly multiply, this causes them to take all the oxygen out of the water causing all the fish and other organisms to die.
88
What products are formed when an acid and metal oxide / hydroxide react together?
A salt and water are created.
89
What is the equation for the reaction of hydrochloric acid and copper oxide?
Hydrochloric acid + copper oxide ---> copper chloride + water.
90
What effects the type of salt that is made during a neutralization reaction?
The type of salt made depends on what type of acid is used, as hydrochloric acid makes a chloride whereas sulfuric acid makes a metal sulfate and phosphorus makes a metal phosphate.
91
What is the word equation for a reaction between an acid and a carbonate?
Acid + Carbonate ---> Salt + Water + Carbon Dioxide
92
What is produced when an acid and ammonia react?
Ammonium salt is created.
93
What pH is pure water?
Pure water has a pH of 7.
94
What pH do acids have?
Acids have a pH value between 0 and 6.
95
What pH do alkalis have?
Alkalis have a pH value between 8 and 14.
96
What is the range of the pH scale?
The pH scale ranges from 0 to 14.
97
What is an indicator?
An indicator is a substance that changes colour based on how alkali or acidic a substance is.
98
What is the pH of the products in a neutralization reaction?
The pH is 7, as the acid and alkali have 'cancelled each other out.'
