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Inorganic Flashcards

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1
Q

What is the trend in atomic radius across a period?

A

Atomic radius decreases because they have similar shielding but more protons so there is a stronger attraction between outer electrons and the nucleus causing the atomic radius to be reduced

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2
Q

What is the trend in atomic radius down a group?

A

Atomic radius increases because an electron shell is added with every element which increases the distance and shielding between the outer electrons and nucleus, reducing the nuclear attraction

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3
Q

What is the general trend in ionisation energies across the period?

A

Increases as atomic radius is decreasing and nuclear charge is increasing meaning the outer electrons are held more strongly so more energy required

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4
Q

Why does the ionisation energy drop a bit between Mg (3s2) and Al (3s2 3p1)?

A

There is an increase in shielding and 3p orbital has a slightly higher energy level so the electron is on average further from the nucleus meaning electron motor easily lost

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5
Q

Why does the ionisation energy drop a bit between P (3s2 3p3) and S (3s2 3p4)?

A

Have same shielding but in Sulphur electron is being removed from an orbital containing two electrons so the repulsion between the electrons makes it easier to remove

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6
Q

What are the different types of bonding in period 3?
Na, Mg, Al, Si, P, S, Cl, Ar

A

Na, Mg, Al - metallic
Si - macromolecular (covalent)
P, S, Cl - simple molecular
Ar - monatomic

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7
Q

What is the trend in melting points from Na, Mg and Al?

A

Increases as you go across because the nuclear charge and no. of delocalised electrons per ion is increasing so there is greater attraction

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8
Q

What is the trend in melting points from P, S, Cl?

A

P4 S8 Cl2
S has highest melting point as has highest Mr so has the strongest VDW of the three where as Cl has the weakest

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9
Q

Why does Ar have the lowest melting point in period three?

A

Full outer shell of electrons so atom very stable and only has very VDW forces between them

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10
Q

What is the trend in melting points down group 2?

A

Decreases as they all have two delocalised electrons per ion but the size of the metallic ion increases down the group meaning the attraction becomes weaker as has to act over a greater distance

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11
Q

What type of reaction happens between water and group 2 metals?

A

redox

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12
Q

What is the reaction between group 2 metals and water?

A

M + 2H2O –> M(OH)2 + H2

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13
Q

Which group 2 metal reacts differently with steam?

A

magnesium

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14
Q

What is the reaction between magnesium and steam?

A

Mg + H2O (g) –> MgO (s) + H2 (g)

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15
Q

What is the trend in reactivity down group 2?

A

Reactivity increases as IE decreases meaning it becomes easier to oxidise atoms

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16
Q

What is the trend in solubility of group 2 metal hydroxides down the group? (what is the most soluble)

A

solubility increases - Ba(OH)2 is the most soluble

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17
Q

What is the trend in solubility of group 2 metal sulphates? (what is the most soluble)

A

solubility decreases - MgSO4 most soluble

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18
Q

How is Mg(OH)2 used and why?

A

Used as an antiacid (indigestion tablets) as its insoluble and neutralises acid

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19
Q

How is Ca(OH)2 used?

A

Used in agriculture to neutralise acidic soil

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20
Q

How is BaSO4 used and why?

A

Used as a barium meal (type of medical tracer). Toxic when enters the bloodstream but as its insoluble it can’t be absorbed

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21
Q

How do you test for sulfate ions? (SO4 2-)

A

Add acidified barium chloride (BaCl2 + HCl) and positive result is white ppt formed

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22
Q

Why is barium used to test for SO4 2- ions?

A

most insoluble group 2 sulphate

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23
Q

Why must barium chloride be acidified when testing for sulfate ions?

A

remove any sulphite or carbon impurities

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24
Q

What is the equation for the reaction between barium chloride and sulfate ions?

A

BaCl2 + XSO4 –> BaSO4 + 2XCl

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25
Q

How is titanium extracted from titanium chloride (TiCl4)?

A

magnesium

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26
Q

What type of reaction is the extraction of titanium from titanium chloride using magnesium?

A

displacement

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27
Q

What is the role of magnesium in the extraction of titanium from titanium chloride?

A

reducing agent (electron donor)

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28
Q

What is the equation for the extraction of titanium from titanium chloride using magnesium?

A

TiCl4 + 2Mg –> 2MgCl2 + Ti

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29
Q

What is flue gas?

A

gases emitted from industrial exhausts and chimneys (SO2 sulphur dioxide)

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30
Q

How do we prevent flue gases entering the atmosphere?

A

using CaO (lime) or CaCO3 (limestone)

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31
Q

What is the reaction when CaO is used to remove flue gases (SO2)? What is the product called

A

CaO (s) + 2H2O (l) + SO2 (g) –> CaSO3 (s) + 2H2O

CaSO3 = calcium sulfite

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32
Q

What is the reaction when CaCO3 is used to remove flue gases (SO2)?

A

CaCO3 (s) + 2H2O (l) + SO2 (s) –> CaSO3 (s) + 2H2O + CO2 (g)

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33
Q

What do you observe when you react group 2 metal with excess water?

A

colourless solution and effervescence

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34
Q

What is the trend in solubility of group2 metals in water?

A

Solubility increases down group
Ba most soluble

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35
Q

Why do isotopes have same chemical properties?

A

same electron configuration

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36
Q

What is the trend in atomic radius down group 7?

A

increases down group due to additional electrons shells

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37
Q

What is the trend in reactivity down group 7?

A

Reactivity decreases down group as increased size and shielding makes it harder to gain electrons

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38
Q

What is the trend in ionisation energy down group 7?

A

decreases due to increased atomic radius and shielding

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39
Q

What is the trend in boiling points down group 7?

A

They’re simple covalent molecules which are held together by VDW so bp increases down group as Mr increases meaning VDW are stronger

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40
Q

What state are the halogens at room temperature?

A

F gas
Cl gas
Br liquid
I solid

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41
Q

What is the trend in electronegativity down group 7?

A

decreases down the group as atomic radius and shielding increases making them worse at attracting the shared pair of electrons

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42
Q

What is the trend in oxidising power (ability as an oxidising agent) of halogens down the group?

A

Oxidising power (ability to accept electrons) decreases down the group as their ability to attract electrons decreases due to the increase in atomic radius and shielding.

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43
Q

When will a halogen displace a halide?

A

If the halide is beneath it
So Cl2 will displace Br-

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44
Q

Are the halide ions good reducing agents or oxidising agents?

A

reducing agents because they are good at donating electrons

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45
Q

What is the trend in the reducing power of halides down the group?

A

reducing power increases as electrons are more easily lost from larger ions

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46
Q

What is the reaction between Fluoride ions and sulphuric acid and what’s the observations? Is it redox?

A

NaF + H2SO4 –> NaHSO4 + HF
misty white fumes of HF
not redox

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47
Q

What is the reaction between Chloride ions and sulphuric acid and what’s the observations? Is it redox?

A

NaCl + H2SO4 –> NaHSO4 + HCl
misty white fumes of HCl
not redox

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48
Q

What is the reaction between Bromide ions and sulphuric acid and what’s the observations? Is it redox?

A

NaBr + H2SO4 –> NaHSO4 + HBr
misty white fumes of HBr
not redox

2HBr + H2SO4 –> Br2 + SO2 + 2H2O
chocking fumes SO2
brown fumes Br2
redox

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49
Q

What is the reaction between Iodide ions and sulphuric acid and what’s the observations? Is it redox?

A

NaI + H2SO4 –> NaHSO4 + HI
misty white fumes of HI
not redox

2HI + H2SO4 –> I2 + SO2 + 2H2O
chocking fumes SO2
black solid I2
redox

6HI + SO2 –> H2S + 3I2 + 2H2O
bad egg smell H2S
redox

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50
Q

Why does the HCl and HF produced from reacting halides with sulphuric acid not react further?

A

Aren’t strong enough reducing agents

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51
Q

How do you test for halides?

A

add dilute HNO3
add few drops of AgNO3

double check by adding ammonia solution

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52
Q

Why do you add dilute nitric acid when testing for halides?

A

To remove any ions that might interfere with the test

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53
Q

Why do we use AgNO3 when testing for halides?

A

Reacts to form a different coloured ppt depending on what ion is present

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54
Q

What is the ionic equation the test for halides?

A

Ag+ + X- —> AgX (s)

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55
Q

Why do you use ammonia solution when testing for halides?

A

silver halides have different solubilities

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56
Q

What happens when you add NH3 (aq) to silver halides?

A

chloride - dissolves in dilute
bromide - dissolves in conc.
iodide - insoluble

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57
Q

What is the reaction of chlorine and cold water?

A

Cl2 (g) + H2O (l) –> HClO + HCl

HClO is chlorate ions

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58
Q

What type of reaction is the reaction of chlorine and water to make chlorate and chloride ion and why?

A

disproportionation as chlorine is both oxides and reduced

ClO- and Cl-

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59
Q

What is the reaction of chlorine and water in the presence of UV light?

A

2Cl2 + 2H2O –> 4HCl + O2

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60
Q

What do we do with chlorate ions and why?

A

Added to water to make it drinkable and to pools as kills bacteria

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61
Q

What are the benefits of chlorinated water?

A

Kills disease causing microorganisms
Can persist in the water and prevent infection further down the supply
Prevents growth of algae, eliminating bad tastes and smells
Removes discolouration caused by organic compounds

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62
Q

What are the risks of chlorinated water?

A

Chlorine gas is very harmful if breathed in, irritates respiratory system
Liquid chlorine can cause burns
Chlorine reacts with a variety of organic compounds and forms carcinogenic (cancer causing) chlorinated hydrocarbons

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63
Q

What do you react chlorine with to make bleach?

A

cold, aqueous NaOH

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64
Q

What is the reaction between sodium hydroxide and chlorine to make bleach?

A

2NaOH + Cl2 –> NaClO + H2O + NaCl

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65
Q

What is the overall reaction between solid sodium bromine and conc. sulfuric acid?

A

2NaBr+2H2SO4 →Na2SO4 +Br2 +SO2 +2H2O

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66
Q

What is more reative sodium or magnesium?

A

Sodium as when it reacts it forms +1 ion so requires less energy to lose one electron as opposed to the two of magnesium

67
Q

What are some observation when sodium reacts with cold water?

A

vigorous reaction, forms a molten ball on the surface of the water
fizzing, prodding H2 (g)

68
Q

How alkaline is the solution after magnesium reacts with cold water?

A

Mg(OH)2 weakly alkaline as not vary soluble so few OH- ions
pH = 9-10

69
Q

Observations when magnesium reacts with cold water?

A

reacts very slowly, thin coating of Mg(OH)2 forms on the surface of the metal

70
Q

What is the oxide formed with Na and how does it react? and type of bonding?

A

Na2O
vigorous
ionic

71
Q

What is the oxide formed with Mg and how does it react? and type of bonding?

A

MgO
vigorous
ionic

72
Q

What is the oxide formed with Al and how does it react? and type of bonding?

A

Al2O3
slow (faster if powdered)
ionic (partially covalent)

73
Q

What is the oxide formed with Silicon and how does it react? and type of bonding?

A

SiO2
slow
giant covalent structure (macromolecular)

74
Q

What is the oxide formed with phosphorus (V) and how does it react? and type of bonding?

A

P4O10
spontaneously combusts
simple molecular

75
Q

What is the oxide formed with sulphur and how does it react? and type of bonding?

A

SO2
burns steadily
simple molecular

(add vanadium catalyst and you get SO3)

76
Q

Explain trend in melting points of period 3 metal oxides? Na, Mg, Al

A

All have high m.p as they form giant ionic lattices

Mg higher than Na as +2 ions from stronger bonds

Al lower than Mg as small electronegaitivty difference between Al and O so oxygen ions don’t attract the electrons as strongly making the bond partially ionic

77
Q

Why does Al2O3 have a lower mp than expected?

A

Small electronegativity difference between Al and O means oxygen ions don’t attract electrons as strongly making the bonds partially covalent

78
Q

Why are mp of P4O10 and SO2 significantly lower than that of other period 3 oxides?

A

simple molecular structures so only have weak VDW

79
Q

Reaction of P4O10 and water?

A

P4O10 (s) + 6H2O –> 4H3PO4
(phosphoric acid)

80
Q

Reaction of SO2 and water?

A

SO2 (g) + H2O –> H2SO3
(sulphurous acid)

81
Q

Reaction of SO3 and water?

A

SO3 (l) + H2O –> H2SO4
(sulfuric acid)

82
Q

Why is SiO2 insoluble in water?

A

giant covalent structure but it is still acidic as can neutralise a base

83
Q

Why is Al2O3 insoluble in water?

A

as its partially covalent (needs to be polar)

84
Q

What does amphoteric mean?

A

can act as an acid or a base

85
Q

Does Al2O3 act as a base or an acid?

A

both its amphoteric

86
Q

How does SiO2 neutralise sodium hydroxide?

A

SiO2 (s) + 2NaOH –> Na2SiO3 + H2O

87
Q

How does P4O10 neutralise sodium hydroxide?

A

P4O10 (s) + 12 NaOH –> 4Na3PO4 + 6H2O

88
Q

How does SO2 neutralise sodium hydroxide?

A

SO2 (g) + 2NaOH –> Na2SO3 + H2O

89
Q

How does SO3 neutralise sodium hydroxide?

A

SO3 (g) + 2NaOH –> Na2SO4 + H2O

90
Q

How does Al2O3 act as a base?

A

Al2O3 (s) + 3H2SO4 –> Al2 (SO4)3 + 3H2O

91
Q

How does Al2O3 act as an acid?

A

Al2O3 (s) + 2NaOH + 3H2O –> 2Na Al (OH)4

92
Q

What are transition metals?

A

Elements in the d block of the periodic table with a partially filled d orbital

93
Q

What are the physical properties of transition metals?

A

high densities
high mp and bp
ionic radii are pretty much the same

(all have similar physical properties)

94
Q

What are the chemical properties of transition metals?

A

Can from complex ions
Form coloured ions
Good catalysts
Exist in variable oxidation states

95
Q

What is a complex?

A

Central metal atom or ion surrounded by co-ordinately bonded ligands

96
Q

What is a ligand?

A

atom/ion/molecule that donates a pair of electrons to a central transition metal ion to form a co ordinate bond

97
Q

What is a coordination number?

A

No. of coordinate bonds bonded to central metal atom/ion

98
Q

What is the shape of a 6 coordinate bond complex and an example?

A

Octahedral
[Fe(H2O)6] 2+ (aq)

99
Q

What is the shape of a 4 coordinate bond complex and an example?

A

Tetrahedral
[CuCl4] 2-

100
Q

What is the shape of a 2 coordinate bond complex and an example?

A

linear
[Ag(NH3)2] + (tollens reagent)

101
Q

What is Tollens reagent and how is it used?

A

[Ag(NH3)2] +
test to distinguish between aldehydes and ketones

102
Q

What is the oxidation state of the central metal ion of a complex ion?

A

(total ox. state of complex) - (ox. state of all ligands)

103
Q

What must a ligand have in order to form a coordinate bond?

A

At least one lone pair

104
Q

What are ligands that only from one coordinate bond called and give examples?

A

monodentate
NH3, H2O, Cl-

105
Q

What are ligands that form two coordinate bonds called and give examples?

A

bidentate

ethane - 1,2 - diamine :NH2CH2CH2:NH2

ethanedioate ions O:OCCOO:

106
Q

What are ligands that form more than two coordinate bonds called and give examples?

A

multi dentate
EDTA 4-

107
Q

What is the central transition metal ion in haemoglobin?

A

Fe 2+

108
Q

What its haemoglobin?

A

A protein found in blood that helps to transport oxygen around the body

109
Q

What is the Haem part of Haemoglobin?

A

Four nitrogen’s coordinately bonded to a Fe 2+ which all come from same multidentate ligand

110
Q

What is the globin part of haemoglobin?

A

The other two coodrinate bonds in haemoglobin come from either water or oxygen and then a protein called groin which has a lone pair on a nitrogen that can coordinately bond to the Fe 2+

111
Q

How does haemoglobin carry oxygen round the body?

A

In the lungs (where oxygen conc. is high) an oxygen molecule is substituted for the water ligand and bonds coordinately to the Fe 2+ to from oxyhemoglobin which is then carried around the body in the blood

When the oxyhaemoglobin gets to a place where oxygen is needed, the oxygen molecule is exchanged for a water molecule and then it returns to the lungs to repeat the process again

112
Q

What happens to haemoglobin when CO is inhaled?

A

The haemoglobin swaps its water ligand for a carbon monoxide ligand forming carboxyhemoglobin. CO is a strong ligand so doesn’t swap with water or oxygen molecules meaning the haemoglobin can no longer transport oxygen so CO poisoning starves the organs of oxygen

113
Q

What happens when a ligands substituted or exchanged?

A

usually a colour change

114
Q

How do you form a more stable complex?

A

Multidentate ligand instead of mono dentate ones

115
Q

When is a reaction not reversible (complex ions)?

A

If new ligand form stronger bonds

116
Q

What is the Chelate effect?

A

Positive entropy change is favourable so monodenatate lingands are substituted with bidentate and multidentate ligands (more moles on RHS)

eg [Fe (H2O)6]3+ + EDTA 4- –> [Fe (EDTA)]- +6H2O) more moles formed so favourable

117
Q

What types of isomerism can complex ions show and when do they occur?

A

optical isomerism - when octahedral complexes have three bidentate ligands co.ord bonded

cis-trans isomerism (special type of EZ) - octahedral and square planar complexes

both types of stereoisomerism

118
Q

What is an example of square planar isomerism and what is it called?

A

transplatin and cisplatin

Pt central ion with two NH3 and two Cl-

EZ stereoisomerism

119
Q

How is cisplatin used and what are the side effects?

A

Anti-cancer drug

hair loss

120
Q

When oxidation sate of vanadium is +5 what is the ion formula and ion colour?

A

VO2 +
yellow

121
Q

When oxidation sate of vanadium is +4 what is the ion formula and ion colour?

A

VO (2+)
blue

122
Q

When oxidation sate of vanadium is +3 what is the ion formula and ion colour?

A

V 3+
green

123
Q

When oxidation sate of vanadium is +2 what is the ion formula and ion colour?

A

V 2+
violet

124
Q

What is the enthalpy change for ligand substitution reactions like?

A

enthalpy change is small as bonds being formed are very similar to the bonds that were broken

125
Q

How are the different oxidation states of vanadium produced?

A

Oxidation of vanadium by zinc in acidic solution

126
Q

What determines weather a transition metal is oxidised or reduced?

A

pH

127
Q

What is required for ions to be reduced?

A

acidic conditions

128
Q

How can you identify a transition metal ion?

A

its colour

129
Q

What does the colour of a transition metal ion complex depend on?

A

coordination number
type of ligands
oxidation state of transition metal

130
Q

How does colour arise in transition metals?

A

When some of the wavelengths of visible light are absorbed and the remaining wavelengths are reflected and transmitted to the human eye. The reflected wavelengths correspond to a specific colour

131
Q

What happens to d electrons when light is absorbed?

A

move from the ground state to an excited state as they’ve gained energy

132
Q

How do you calculate the energy change of electrons when they are excited?

A

E = hf
f is the frequency of light emitted
h is planck constant

133
Q

What is colorimetry?

A

An analytical technique that uses absorption of visible light to determine the conc. of coloured ions by measuring absorbance

134
Q

How do you find the conc. of a coloured solution using a colorimeter?

A

White light is shone through a filter (which has been chosen so that it only lets through the colour of light that is absorbed by the sample)

The light then passes through the sample to the colorimeter which calculates how much light was absorbed by the sample

The more concentrated the solution the more light it will absorb

You can then use a calibration curve (which is made by measuring the absorbance of known concentrations) and then read off the graph

135
Q

Why are the energies of the d orbitals of the metal ion raised when ligands are bonded to it and what happens to the d orbitals?

A

Because of the repulsion between the electrons in the ligands and the electrons in the d orbitals of the metal ions.

However cause of how they’re arranged in space it doesn’t raise all their energies by the same amount. Instead it splits them into two groups

136
Q

What is a heterogeneous catalyst and give an example?

A

A catalyst that is in a different phase or state to the species in the reaction

Iron catalyst in the Haber process

137
Q

Why do transition metals make good catalysts?

A

Variable oxidation states

electrons are transferred to produce a reactive intermediate and speed up the reaction rate

138
Q

What is the overall reaction for the Contact Process?

A

2SO2 + O2 –> 2SO3

V2 O5 catalyst

139
Q

What are the intermediate reactions in the Contact Process?

A

V2O5 + SO2 –> V2O4 + SO3

V2O4 + 1/2 O2 –> V2O5

140
Q

What is a homogenous catalyst?

A

A catalyst that is in the same phase/state as the species in the reaction

141
Q

How does a heterogenous solid catalyst work?

A

adsorbs molecules onto an active site on the surface of the catalyst

142
Q

How does adsorption work?

A

It adsorbs different species to the active site and increases the proximity of molecules and weakens the covalent bonds in the molecules so that reactions occur more easily and the rate is increased

143
Q

What does the strength of adsorption depend on?

A

Type of catalyst

144
Q

Why do iron, cobalt and nickel make the best catalysts?

A

relatively cheap and increase the rate of reaction the most out of period 4 metals

145
Q

What type of catalysts can be poisoned by impurities?

A

heterogenous

146
Q

What is catalyst poisoning?

A

When impurities block the adsorption site preventing adsorption

which means bonds of molecules remain strong and the catalyst has no effect on the rate of reaction

147
Q

What is the problem with catalyst poisoning?

A

means an increase in chemical production costs as catalyst has to be replaced or cleaned regularly

148
Q

What impurities poison the solid iron catalyst used in the Haber process?

A

sulfur impurities

149
Q

What impurities poison the rhodinium in catalytic converters?

A

lead

150
Q

What is a catalytic converter?

A

Turns toxic gases and pollutants into less harmful gases

151
Q

Equation for catalytic converter and catalyst used? (CO and NO)

A

2CO (g) + 2NO (g) –> 2CO2 (g) + N2 (g)
solid rhodinium and platinum

152
Q

How do catalytic converters get poisoned?

A

When leaded petrol is used, the lead sticks to the catalytic converters so theyre no longer effective

153
Q

Why does S2O8 (2-) and I- need a catalyst to react?

A

Both anions so would naturally repel and never react

154
Q

What catalyst is used when reacting S2O8 (2-) and I-?

A

Fe 2+ or Fe 3+

155
Q

Overall reaction between S2O8 (2-) and I-?

A

2S2O8 (2-) + 2I- –> I2 + 2SO4 (2-)
Fe 2+ or Fe 3+ catalyst

156
Q

What are the intermediate reactions of S2O8 (2-) with I -?

A

S2O8 (2-) + 2Fe 2+ –> 2SO4 (2-) + 2Fe 3+
2Fe 3+ + 2I- –> 2Fe 2+ + I2

can happen in any order hence why both Fe2+ and Fe3+ can be used

157
Q

What is autocatalysis?

A

When something catalyses itself

158
Q

How do homogenous catalysts work?

A

They work by combining with the reactants to produce a reactive intermediate. This changes the reaction path as the enthalpy change for the formation of the intermediate is much lower than the original reaction.

So activation energy is lower and the reaction is more feasible

159
Q

What happens to the rate of reaction when something is an autocatalyst?

A

As the amount of product increases the rate of reaction increases as it becomes catalysed

160
Q

What is the autocatalyst when MnO4 - and C2O4 (2-) react?

A

Mn 2+

161
Q

What is the overall reaction between MnO4 - and C2O4 (2-)?

A

2MnO4- + 5C2O4 (2-) + 16H+ –> 2Mn2+ + 10CO2 + 8H2O

162
Q

What are the intermediate reactions of the reaction between MnO4- and C2O4 (2-) where Mn2+ acts as an autocatalyst?

A

4Mn2+ + MnO4- + 8H+ –> 5Mn3+ + 4H2O

2Mn3+ + C2O4 (2-) –> 2CO2 + 2Mn2+

163
Q

What increases efficiency of heterogenous catalysts?

A

larger surface area by using powder or coating mesh with the catalyst

Chemistry (10 decks)

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