Inorganic and physical chemistry - part 1

Question 1

What is dual nature?

Answer 1

term used to describe light/matter as being able to be both waves and particles

Question 2

what is a photon?

Answer 2

• particles of electromagnetic radiation

- bundles of fixed energy

Question 3

what happens when matter emits a photon of radiation?

Answer 3

electrons are moving to a lower energy

Question 4

what is atomic emission spectroscopy used for?

Answer 4

used in identification of unknown substances

Question 5

how is a photon of light emitted?

Answer 5

• electrons absorb energy and become excited
• move to higher energy level
• on moving down to lower energy level, a photon of light is emitted

Question 6

what is the energy difference of an electron transition related to?

Answer 6

the wavelength of light

Question 7

how would you find the quantity of a substance when using AES?

Answer 7

measure the intensity of emitted radiation

Question 8

what does AES give evidence for?

Answer 8

gives evidence that electrons occupy energy levels as it shows a number of lines of fixed frequency, corresponding to precise emissions of energy

Question 9

what is ionisation energy?

Answer 9

energy required for electron to break away from the atom

Question 10

what does ionisation energy correspond to?

Answer 10

the difference in energy between the ground state and the convergence limit

Question 11

what does each line on the emission spectrum represent?

Answer 11

a photon of light

Question 12

what produces a photon of light on the emission spectrum

Answer 12

an electron falling from a higher energy state to a lower energy state

Question 13

what does atomic absorption spectroscopy measure?

Answer 13

measures the absorbed radiation needed to promote electrons to higher energy levels

Question 14

in the Bohr model what is fixed?

Answer 14

enthalpy change

Question 15

what is represented by the Bohr model?

Answer 15

• electrons and energy levels

- photons emitted during transitions

Question 16

what is Heisenburg’s uncertainty principle?

Answer 16

impossible to simultaneously know both the location and momentum of an electron

Question 17

what are the 4 quantum numbers?

Answer 17

• principal
• angular momentum
• magnetic
• spin

Question 18

what does the principal (n) quantum number represent?

Answer 18

energy, size

Question 19

what does the angular momentum quantum number represent?

Answer 19

shape

Question 20

what does the magnetic quantum number represent?

Answer 20

multiplicity, orientation

Question 21

as the principal quantum number (n) increases what happens to the energy and size of orbital?

Answer 21

• energy increases

- orbital is larger

Question 22

when l=0 (angular momentum) what type of orbital is it?

Answer 22

s-orbital

Question 23

what shape is an s-orbital?

Answer 23

spherical

Question 24

what shape is a p-orbital?

Answer 24

dumbell

Question 25

when l=1 what type of orbital is it?

Answer 25

p-orbital

Question 26

when l=2 what type of orbital is it?

Answer 26

d-orbital

Question 27

when l=3 what type of orbital is it?

Answer 27

f-orbital

Question 28

state Pauli exclusion principal

Answer 28

- no two electrons can share a set of quantum numbers | - electrons have the property of spin

Question 29

what does degenerate mean?

Answer 29

having equal energy

Question 30

state Hund's rule

Answer 30

when degenerate orbitals are available, electrons fill each degenerate orbital singly and with parallel spins before pairing up to fill orbitals

Question 31

what is Aufbau principle?

Answer 31

filling orbitals in order of increasing energy

Question 32

what is the order of orbitals?

Answer 32

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p

Question 33

what is special about transition metals and their orbitals?

Answer 33

they have an incomplete d-orbital in at least on of their ions

Question 34

when a transition metal forms an ion, electrons are removed from which orbital first - 3d or 4s

Answer 34

4s

Question 35

why is there some irregularities in the trends for first ionisation energy?

Answer 35

some elements have a special stability as they have a full or half-full shell which requires more energy to remove an electron

Question 36

orientation of electron pairs around a central atom, is arranged to minimise what?

Answer 36

repulsion

Question 37

what is a dative covalent bond?

Answer 37

both electrons in the bond originate on the same atom

Question 38

shape - 2 bonding pairs

Answer 38

linear

Question 39

shape - 3 bonding pairs

Answer 39

trigonal planar

Question 40

shape - 4 bonding pairs

Answer 40

tetrahedral

Question 41

shape - 5 bonding pairs

Answer 41

trigonal bipyramidal

Question 42

shape - 6 bonding pairs

Answer 42

octahedral

Question 43

what is the colour of compound related to?

Answer 43

the oxidation state of the transition metal

Question 44

does oxidation cause an increase or decrease in the oxidation number?

Answer 44

increase

Question 45

does reduction cause an increase or decrease in the oxidation number?

Answer 45

decrease

Question 46

what is the oxidation number of an element or molecule?

Answer 46

zero

Question 47

what is the oxidation number of an ion?

Answer 47

the charge

Question 48

what makes a good oxidising agent?

Answer 48

a high oxidation state

Question 49

what makes a good reducing agent?

Answer 49

a low oxidation state

Question 50

what is the co-ordination number?

Answer 50

total number of bonds from the ligand to the central metal ion

Question 51

what is a complex?

Answer 51

a central metal ion surrounded by ligands

Question 52

what is a ligand?

Answer 52

negative ions or uncharged molecules with one or more non-bonding pairs of electrons

Question 53

what type of bonds do ligands form?

Answer 53

dative bonds

Question 54

when would a ligand be described as monodentate?

Answer 54

when it donates one pair of electrons to the central metal ion

Question 55

when a ligand donates 2 pairs of electrons to the central metal ion it is described as being what?

Answer 55

bidentate

Question 56

if a complex is overall negative what does the name end in?

Answer 56

-ate

Question 57

why are transition metal compounds coloured?

Answer 57

a d-d transition occurs

Question 58

what is a d-d transition?

Answer 58

electron from one of the lower energy d orbitals is promoted to a higher energy d orbital

Question 59

what colour is observed in metals?

Answer 59

the complimentary colour to that absorbed

Question 60

what does the spectrochemical series show?

Answer 60

the ability of ligands to cause the splitting of d orbitals

Question 61

if there is a large difference in energy in the d-orbitals what is produced?

Answer 61

strong field ligands

Question 62

if there is a small difference in energy in the d-orbitals what is produced?

Answer 62

weak field ligands

Question 63

why is a solution colourless?

Answer 63

no d electrons, so no d-d transitions can occur

Question 64

what is used to study the effects of d-d transitions?

Answer 64

spectroscopy

Question 65

what is a homogeneous catalyst?

Answer 65

catalyst in the same physical state as the reactants

Question 66

what is a heterogeneous catalyst?

Answer 66

catalyst in a different physical state as the reactants

Question 67

what are the three main steps to a heterogeneous catalyst?

Answer 67

- adsorption - reaction - desorption

Question 68

describe adsorption (in terms of a heterogeneous catalyst)

Answer 68

- molecules of one or both reactants form bonds with the catalyst - weakens bonds within molecules

Question 69

describe reaction (in terms of a heterogeneous catalyst)

Answer 69

- the molecules react on the catalyst surface

Question 70

describe desorption (in terms of a heterogeneous catalyst)

Answer 70

- the product molecules leave the catalyst | - vacant site can be occupied by another reactant molecule

Question 71

how does a catalyst speed up a reaction?

Answer 71

- by presence of unpaired electrons or unfilled d-orbitals - allows intermediate complexes to form - provides reaction pathways or lower energy

Question 72

what makes transition metals good catalysts?

Answer 72

they have variable oxidation states