Topic 5 - Separate Chemistry 1 Flashcards

(83 cards)

1
Q

What are the typical properties of transition metals?

A
Hard, strong and shiny
Malleable
Conductive
High MP/BP
High densities
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2
Q

What do transition metals make?

A

Good catalysts

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3
Q

What must you be able to recall that most metals are transition metals and that their
typical properties include?

A

High melting point
High density
The formation of coloured compounds
Catalytic activity of the metals and their compounds (exemplified by iron)

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4
Q

What are most transition metals visually wise?

A

Colourful

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5
Q

Name one industrial process that uses a transition metal catalyst and name the catalyst used?

A

Haber process and iron

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6
Q

Rubidium is a Group 1 metal
Palladium is a transition metal
Predict which of these two metals will have a higher densitiy

A

Palladium as it is a transition metal therefore its density will be larger than rubidium

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7
Q

Why are pure metals malleable?

A

Because they have a regular arrangement of identical ions that can slide over each other

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8
Q

What are alloys?

A

Metals made up of another element

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9
Q

What can alloys be made of?

A

Metal + Non-metal
or
Metal + Metal

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10
Q

How do alloys make stronger compounds?

A

Because different elements have different sized atoms therefore it will be much harder for the ions to slide over each other

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11
Q

Why is iron often alloyed?

A
To make it stronger and harder
Prevent rust (corrosion)
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12
Q

Why is gold alloyed?

A

To make it stronger

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13
Q

What are aluminium alloys used in?

A

Aircraft manufacture

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14
Q

What is steel used for?

A

Bridges, cutlery, washing machines, pans, ships and tools

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15
Q

Explain why alloys of aluminium are used instead of pure aluminium for building aircraft?

A

Aluminium is not strong enough on its own for making aeroplanes therefore it is alloyed with small amounts of other metals to increase its strength

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16
Q

What type of a reaction is the rusting of iron?

A

A redox reaction

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17
Q

What must be in the presence for metals to corrode?

A

Oxygen and water

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18
Q

Why is rusting a redox reaction?

A

The metal loses electrons so it is oxidised whilst the oxygen gains electrons therefore the oxygen gets reduced

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19
Q

How do you test rusting?

A

Test with water but no oxygen, no water but oxygen and both]

rusting will only occur in last

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20
Q

When testing for rust how do you remove oxygen?

A

Oil

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21
Q

When testing for rust how do you remove water?

A

Add calcium chloride

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22
Q

How can you prevent rusting?

A

Painting
Oiling or greasing
Sacrifical protection

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23
Q

When is oil/grease used to prevent rusting?

A

When moving parts are involved

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24
Q

What is involved in galvanising?

A

A coat of zinc over iron

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25
Why does galvanising work?
Because zinc is more reactive than iron, it'll lose electrons and corrode in preference to iron
26
What is electroplating?
Coating the surface of a metal with another metal
27
How is electroplating done?
Using electrolysis
28
When electroplating, what is the cathode?
The object you're going to electroplate
29
When electroplating, what is the anode?
The bar of metal you're using for the plating
30
When electroplating, what is the electrolyte?
The solution containing the metal ions of the metal you're plating
31
What type of metals are used for protection?
Unreactive and don't corrode easily
32
When electroplating silver onto a brass cup? | Describe where everything is?
Cathode is the brass cup Anode is a bar of pure silver Electrolyte is silver solution
33
Outline how bolting some magnesium onto a piece of iron will prevent it from rusting?
Magnesium is more reactive than iron so will lose electrons/be oxidised/react with water and oxygen in preference to iron
34
What does titration allow you to find out?
Exactly how much acid is needed to neutralise a given quantity of alkali (vice versia)
35
When undergoing titration, why can't you use universal indicator?
Because it changes colour gradually and you won't get a single colour change
36
How do you undergo titration
Use a pipette to measure out a set volume of alkali into a flask Add drops of an indicator FIll a burette with a known conc/vol of acid Slowly add acid until end point Repeat without indicator
37
What is the formula for concentration (mol/dm^3)?
Concentration = Number of moles / Volume
38
How do you convert M into g/dm^3?
Times by the RF
39
What is the yield?
The amount of product you get from a reaction
40
What is the percentage yield equation?
Percentage Yield = Actual Yield / Theoretical Yield
41
Why don't you always get a 100% yield?
Incomplete reactions - not all of the reactants have reacted Practical losses - chemicals being lost between transfer of containers Unwanted reactions - unexpected reactions happening
42
What does the atom economy tell you?
What percentage of the mass of reactants have been converted into your desired product
43
Whats the atom economy equation?
Atom Economy = Total Mr of desired products / Total Mr of all products
44
What does a 100% atom economy mean?
All of the atoms in the reactants have been turned into useful products
45
What do low atom economies do?
Use up resources very quickly and make alot of waste
46
When designing an industrial process, what must you consider?
The cost of extracting and refining the raw materials Energy costs Whether you can control the conditions or not
47
What is the haber process equation?
N2 + 3H2 ⇌ 2NH3 (+ heat)
48
In the haber process where does higher pressures favour?
The forward reaction as there are more moles on the left
49
What is the pressure for the haber process?
200 atmospheres
50
What ratio is hydrogen and nitrogen mixed in?
3:1
51
What temperature is best for the haber process equilibrium wise?
Low because the forward reaction is exothermic
52
Why isnt the haber process done in cold temperatures?
Because the cold temperatures althought means a higher yield the reaction rate will be much slower
53
What temperature is the haber process done at?
450*C
54
What catalyst is used in the haber process?
Iron catalyst
55
What doens't the ccatalyst affect within the haber process?
The position of equilibrium or the % yield
56
A pressure of 200 atm is used in the production of ammonia What would happen to the yield of ammonia if a higher pressure was used? Explain your answer?
There would be more ammonia made as there is a higher number of moles on the left therefore more product will be made to balance that out
57
What do fertilisers often contain?
Nitrogen, phosphorus and potassium compounds
58
Whats the point of fertilisers?
To promote plant grow
59
What are the advantages of using ammonia for fertilisers?
You can control the compositions of chemicals in them | Soluble so can dissolve down into the soil to reach the plant
60
What is the advantage of using ammonium salts?
THEY ARE ALWAYS SOLUBLE
61
How do you make an ammonium salt?
Titration
62
Give the steps to make an ammonium salt?
Add a few drops of methyl orange indicator to the ammonia solution Add the acid until the colour change Repeat without indicator, then to get the ammonium crystals you can gently evaporate the solution (crystallise)
63
Why isn't the titration method used in industry?
It's extremely impractical for large quantities and using crystallisation is too slow
64
What is the definiton of molar volume?
The volume occupied by ONE MOLE OF A GAS
65
What are the units for molar volume?
dm^3/mol
66
What is the molar volume equation?
Molar volume = Gas volume / Number of moles
67
Whats the volume of 4.5 moles of chlorine at RTP?
4.5 x 24 = 108 dm^3
68
How many moles are there in 8280 cm^3 of hydrogen gas at RTP?
8280 / 1000 = 8.28 | 8.28 / 24 = 0.345 moles
69
The Mr of methane is 16 | What volume will 36g of methane gas occupy at RTP?
``` Moles = Mass / Mr Moles = 36 / 16 Moles = 2.25 ``` ``` Volume = Moles x 24 Volume = 2.25 x 24 Volume = 54 dm^3 ```
70
What do fuel cells use?
Fuel and oxygen
71
What do fuel cells do?
Produce electrical energy
72
When does a fuel cell stop?
When one of the reactants is used up
73
What is produced in a hydrogen-oxygen fuel cell?
Water
74
What is the equation for a hydrogen-oxygen fuel cell?
Hydrogen + Oxygen -> Water | 2H2 + O2 -> 2H2O
75
What are the advantages of using hydrogen-oxygen fuel cells?
Fewer places to lose energy through heat No moving parts so no loss of energy through friction No production of greenhouse gases, nitrogen oxides, sulfur dioxide, carbon monoxide
76
What are the disadvantages of using hydrogen-oxygen fuel cells?
Since hydrogen is a gas, it is hard to store Hydrogen is very explosive so it's difficult to safely store Hydrogen is made from hydrocarbons or by the electrolysis of water (both use electricity- which usually involves fossil fuels)
77
What are the properties of magnalium?
Lighter, stronger and less corrosive than aluminium
78
What does 18 carat gold actually mean?
18/24 = 75% pure gold
79
What element is added to iron to make steel?
Carbon
80
Give the two main reasons electroplating is done?
Improve the appearance of metals | Reduce corrosion
81
What does it mean when a reaction has a 100% percentage yield?
All of the predicted products have been made
82
Why aren't reactions with low atom economies usually profitable?
Expensive to source materials and dispose of waste
83
Explain why the conditions used in the haber process are a compromise?
The haber process produces the most yield of ammonia at lower temperatures, however, the lower the temperature of ANY reaction the slower the products are produced, therefore a compromise is met for the most yield per time