ES- Elements of the Sea Flashcards
(100 cards)
0
Q
What is the appearance + state of fluorine at room temperature?
A
Pale yellow gas
1
Q
What is the appearance + state of chlorine at room temperature?
A
Green gas
2
Q
Volatility of fluorine?
A
Gas
3
Q
Volatility of iodine?
A
Sublimes on warming to give a purple vapour
4
Q
Volatility of chlorine?
A
Gas
5
Q
Volatility of bromine?
A
Liquid quickly forms brown gas on warming
6
Q
What is the appearance + state of bromine at room temperature?
A
Dark red liquid
7
Q
What is the appearance + state of iodine at room temperature?
A
Shiny black solid
8
Q
Solubility of iodine in water?
A
Barely soluble, gives brown solution
9
Q
Solubility of bromine in water?
A
Slightly soluble to give red-brown solution
10
Q
Solubility of fluorine in water?
A
Reacts with water
11
Q
Solubility of chlorine in water?
A
Slightly soluble to give pale green solution
12
Q
Solubility of fluorine in organic solvents?
A
Soluble
13
Q
Solubility of iodine in organic solvents?
A
Soluble to give a violet solution
14
Q
Solubility of chlorine in organic solvents?
A
Soluble to give a pale green solution
15
Q
Solubility of bromine in organic solvents?
A
Soluble to give a red solution
16
Q
Which of the halogens is the most reactive?
A
Fluorine
17
Q
Does fluorine react with halide ions and silver ions???
A
NO
18
Q
What would you expect from the reaction of chlorine and silver ions?
A
White precipitate = silver chloride
19
Q
What would you expect from the reaction of bromine and silver ions?
A
Cream precipitate = silver bromide
20
Q
What would you expect from the reaction of iodine and silver ions?
A
Yellow precipitate = silver iodide
21
Q
How does iodine behave in displacement reactions?
A
It does not displace anything
22
Q
How does fluorine behave in displacement reactions?
A
It displaces everything below it in the group (Cl, Br, I)
23
Q
Why are halogens known as oxidising agents?
A
They increase in oxidation state.
They tend to remove electrons from other elements.
24
Are all halogens reactive?
Yep
25
Why is fluorine the strongest oxidising agent in group 7?
Small atoms
| Fewest shells so less shielding from nucleus + greater attraction (pull) from nucleus
26
How does fluorine need to be stored?
It's too reactive
| Made *in situ (as needed)* by *electrolysing liquid hydrogen fluoride*
27
Why is chlorine dangerous?
Toxic + volatile (gas)
28
How is chlorine transported?
Rail or road tanker, stored as a liquid OR produce it on site
29
How do the bond strengths of halogenoalkanes change down the group?
Decrease
30
How is bromine transported?
Convert it into Bromide compounds
*Lead-lined steel tanks*
Tanks are supported in *strong metal frames*
Transport routes planned to minimise risk of accidents
31
How do the reactivities of halogenoalkanes change down the group?
Increase
32
What are the conditions for homolytic fission?
Gas phase; high temperatures/ the presence of UV radiation (e.g. In the stratosphere)
33
What are the conditions for heterolytic fission?
Halogenoalkane dissolved in a polar solvent like ethanol/ water mixture
34
What is a carbocation?
A positively charged C group
35
What reactions do halogenoalkanes undergo?
Nucleophilic substitution
36
How many electrons can S hold?
2
37
How many electrons can P hold?
6
38
How many electrons can D hold?
10
39
How many electrons can F hold?
14
40
How many orbitals does S have?
1
41
How many orbitals does P have?
3
42
How many orbitals does D have?
5
43
How many orbitals does F have?
7
44
What is a cation?
A positive ion
45
What is a giant ionic lattice?
Lots of ions arranged in fixed positions
46
Why can an ionic lattice hold its structure?
The attractive forces are stronger than the repulsive forces
47
What are hydrated crystals?
Crystals of some ionic solids with water molecules fit into the lattice just as regularly as ions
48
What happens when hydrated crystals are heated?
Water is driven off as steam
49
What is the product of heated hydrated crystals?
An anhydrous solid
50
What is the main condition of hydration?
The energy needed to break the lattice is compensated by the energy released
51
What are spectator ions?
Ions that are not involved in ionic equations
52
Give an example of covalent compounds being made from mixed solutions
Neutralisation
53
True or false? 'All NITRATES are soluble'
True
54
Which CHLORIDES are insoluble
AgCl ; PbCl2
55
Most SULFATES are soluble in water. What are the exceptions to this rule?
BaSO4 ; PbSO4 ; SrSO4
56
All CARBONATES are insoluble. What are the exceptions to this rule?
NH4 ; Group 1 elements
57
Are all GROUP 1 salts soluble or insoluble in water?
soluble
58
Name the three types of salts that are always soluble in water
SODIUM, POTASSIUM, AMMONIUM
59
At room temperature and pressure what is the volume that 1 mole of any gas occupies?
24 dm3
60
At standard temperature and pressure what is the volume that 1 mole of any gas occupies?
22.4 dm3
61
Why do chemists usually prefer to measure out quantities in moles rather than grams?
Moles tells us the number of particles actually present
62
How does ATOMIC RADIUS affect the size of ionisation enthalpies?
The bigger the atoms, the weaker the electronegative pull (from the nucleus)
63
How does NUCLEAR CHARGE affect the size of ionisation enthalpies?
The more protons in the nucleus, the stronger the pull from the nucleus
64
How does ELECTRON SHIELDING affect the size of ionisation enthalpies?
The more inner shells the weaker the electrongeative pull (from the nucleus)
65
What is the first ionisation enthalpy?
The energy needed to remove 1 electron from each atom in 1 mole of GASEOUS ATOMS to form 1 mole of GASEOUS 1+ IONS
66
What is the second ionisation enthalpy?
The energy needed to remove 1 electron from each atom in 1 mole of 1+ GASEOUS IONS to form 1 mole of GASEOUS 2+ IONS
67
What is the effect of having more electrons on ionisation enthalpy? (For elements within the same period)
More electrons = More protons. This means a stronger electronegative pull from the nucleus of the atom.
68
What is important about the mole of gaseous atoms/ ions being ionized?
They must be ISOLATED.
69
Why does it get harder to remove electrons from ions?
Once an electron has been removed from the atom/ ion, the electronegative pull increases
70
What is important to note about a graph showing ionisation enthalpies?
A sharp increase in the enthalpy when electrons are taken from the next outer shell. This is because the next shell is closer to the nucleus...
71
How do you identify a spectator ion?
It will be anything that hasn't changed in oxidation state during the reaction.
72
What are oxoanions?
Negative ions with oxygen in them
73
'Electrons in atoms have a spin' What does this mean?
They can only occupy the same orbital with opposite/ paired spins (spinning in opposite directions)
74
What are sub-shells filled with electrons known as?
CLOSED - SHELL ARRANGEMENTS
75
What are halogens more soluble in: organic solvents, or water?
ORGANIC SOLVENTS
76
True or false? Different halogens can covalently bond with each other
True. The less reactive one has a positive oxidation state.
77
What do you add to the test for halide ions FIRST and why?
DILUTE NITRIC ACID - Removes ions which might interfere with the reaction
78
What is the test for halide ions and what would you see?
Silver nitrate - A precipitate of the silver halide
79
What colour is the Chloride precipitate?
WHITE
80
What colour is the Fluoride precipitate?
Trick question: No precipitate would be formed in the presence of silver nitrate because SILVER FLUORIDE is SOLUBLE IN WATER.
81
What colour is the Iodide precipitate?
YELLOW
82
What is the main way of extracting halogens (excl. fluorine)?
Electrolysis of halide solutions
83
What happens when solutions containing I- or Br- ions are electrolysed?
1. Halogen released at anode
| 2. Halogen oxidised to atoms which form molecules
84
What condition must chloride be extracted from in its halide solution?
CONCENTRATION
85
In a chloride solution what two CATIONS are present?
Na+ ; H+
86
In a chloride solution what two ANIONS are present?
Cl- ; OH-
87
If the chloride solution is dilute, what is released at the cathode?
H2 (Hydrogen)
88
If the chloride solution is concentrated, what is released at the cathode?
H2 (Hydrogen)
89
If the chloride solution is dilute, what is released at the anode?
OH- ---> O2 (Oxygen)
90
If the chloride solution is concentrated, what is released at the anode?
Cl- ---> Cl2
91
True or false? Regardless of whether the solution is concentrated or dilute, HYDROGEN is always produced at the CATHODE
True
92
Why can't fluorine be extracted from electrolysis?
Hydroxide ions are discharged regardless of the concentration of the solution
93
What is the atom economy of electrolysis?
100%
94
How is Fluorine transported?
Just avoid using it
95
How is Iodine transported?
This is fairly easy to transport
96
What reactions with halide ions are IRREVERSIBLE?
DISPLACEMENT and REDOX
97
What STATE are molecular dipoles at room temperature and pressure?
LIQUIDS
98
What is the importance of silver halides?
Used in PHOTOCHROMIC LENSES
99
Silver bromide is decomposed by light. What is it soluble in and why is this useful?
SODIUM THIOSULFATE - It clears silver bromide crystals from films
