Unit 1- Inorganic chemistry

Question 1

A photon carries energy proportional to what?

Answer 1

The frequency of radiation

Question 2

The photons in which frequency of radiation can transfer greater amounts of energy?

Answer 2

Those in high frequency radiation transfer greater amounts of energy

Question 3

What can happen to the electrons within atoms when energy is transferred to these atoms?

Answer 3

The electrons can be promoted to higher energy levels

Question 4

When does an atom emit a photon of light energy?

Answer 4

When an excited electron moves from a higher energy level to a lower energy level

Question 5

What happens in absorption spectroscopy?

Answer 5

Electromagnetic radiation is directed at an atomised sample, the radiation is then absorbed as electrons are promoted to higher energy levels

Question 6

What happens in emission spectroscopy?

Answer 6

High temperatures are used to excite the electrons within atoms, as the electrons drop to lower energy levels, photons are emitted

Question 7

In atomic spectroscopy, what is the concentration of the element within a sample related to?

Answer 7

The intensity of light emitted or absorbed

Question 8

What are the 4 different shapes of orbitals?

Answer 8

s, p, d and f

Question 9

How do electrons behave in an atom?

Answer 9

As standing waves. These are waves that vibrate in time but do not move in space. There are different sizes and shapes of standing wave possible around the nucleus, known as orbitals

Question 10

How many electrons can an orbital hold?

Answer 10

A maximum of 2

Question 11

How many electrons can an orbital hold?

Answer 11

A maximum of 2

Question 12

What is the order of the electromagnetic spectrum from highest to lowest energy?

Answer 12

Gamma rays, X-rays, ultraviolet, visible light, infrared, microwaves and radio waves

Question 13

Electrons within atoms have fixed amounts of energy called…?

Answer 13

Quanta

Question 14

It is possible to describe any electron within an atom using four quantum numbers, what are these and what do they tell us about the electron?

Answer 14

• principal quantum number (n)- indicates the main energy level for an electron and is related to the size of the orbital
• angular momentum number (l)- determines the shape of the subshell and can have values from zero to n-1
• magnetic quantum number (m)- determines the orientation of the orbital and can have values between -l and +l
• spin magnetic quantum number (s)- determines the spin and can have values of +1/2 or -1/2

Question 15

What are the 3 rules that determine how electrons within atoms are arranged?

Answer 15

• the aufbau principle
• Hund’s rule
• the Pauli exclusion principle

Question 16

What is the aufbau principle?

Answer 16

Electrons fill orbitals in order of increasing energy

Question 17

What is Hund’s rule?

Answer 17

When degenerate orbitals are available, electrons fill each singly, keeping their spins parallel before spin pairing starts

Question 18

What is the Pauli exclusion principle?

Answer 18

No two electrons in one atom can have the same set of 4 quantum numbers, therefore, no orbital can hold more than two electrons and these two electrons must have opposite spins

Question 19

In an isolated atom, what can be said about the orbitals within each subset?

Answer 19

They are degenerate (have the same energy)

Question 20

The periodic table can be split into 4 blocks (s, p, d and f), which correspond to what?

Answer 20

The outer electronic configuration of the elements within these blocks

Question 21

How are electron pairs arranged?

Answer 21

To minimise repulsion and maximise separation

Question 22

What are the names for the arrangement of electron pairs around a central atom for two through to six electron pairs?

Answer 22

two electron pairs= linear
three electron pairs= trigonal planar
four electron pairs= tetrahedral
five electron pairs= trigonal bipyramidal
six electron pairs= octahedral

Question 23

What is the order of electron pair repulsions in order from most repulsion to least repulsion?

Answer 23

• bonded pair/bonded pair (most repulsion)
• non-bonded pair/bonded pair
• non-bonded pair/non-bonded pair (least repulsion)

Question 24

What are the d-block transition metals?

Answer 24

Metals with an incomplete d subshell in at least one of their ions

Question 25

The filling of d orbitals follows the aufbau principle, with the exception of which two elements and why is this?

Answer 25

Chromium and copper, these exceptions are due to the special stability associated with the d subshell being half filled or completely filled

Question 26

When atoms from the first row of the transition elements form ions, what electrons do they lose first?

Answer 26

The 4s electrons are lost first rather than the 3d electrons

Question 27

What oxidation number do uncombined elements have?

Answer 27

zero

Question 28

What is the oxidation number of ions containing single atoms?

Answer 28

The oxidation number is the same as the charge on the ion

Question 29

In most of its compounds, what is oxygen's oxidation number?

Answer 29

-2

Question 30

In most of its compounds, what is hydrogen's oxidation number?

Answer 30

+1

Question 31

What must the sum of all the oxidation numbers in a neutral compound add up to?

Answer 31

zero

Question 32

What must the sum of all the oxidation numbers in a polyatomic ion add be equal to?

Answer 32

The charge on the ion

Question 33

What can oxidation be defined as?

Answer 33

An increase in the oxidation number

Question 34

What can reduction be defined as?

Answer 34

A decrease in the oxidation number

Question 35

What are oxidising agents often?

Answer 35

Compounds containing metals in high oxidation states

Question 36

What are reducing agents often?

Answer 36

Compounds containing metals in low oxidation states

Question 37

What are ligands?

Answer 37

Negative ions or molecules with non-bonding pairs of electrons that they donate to the central metal atom or ion, forming dative covalent bonds

Question 38

What is a dative covalent bond?

Answer 38

a covalent bond (a shared pair of electrons) in which both electrons come from the same atom

Question 39

What are the classifications of ligands and give examples of each?

Answer 39

- monodentate (NH3, Cl-) - bidenatate (oxalate ion) - hexadentate (EDTA)

Question 40

What is the coordination number of a ligand?

Answer 40

The total number of bonds from the ligands to the central transition metal

Question 41

What can be said about the d orbitals in a complex of a transition metal?

Answer 41

They are no longer degenerate

Question 42

When does the splitting of d orbitals to higher and lower energies occur?

Answer 42

When the electrons present in approaching ligands cause the electrons in the orbitals lying along the axes to be repelled

Question 43

What is the difference between strong and weak field ligands?

Answer 43

Strong field ligands cause a large difference in energy between subsets of d orbitals, weak field ligands cause a small energy difference

Question 44

What are heterogeneous catalysts?

Answer 44

Catalysts which are in a different state to the reactants

Question 45

What are homogeneous catalysts?

Answer 45

Catalysts which are in the same state as the reactants

Question 46

Why is electromagnetic radiation said to have a dual nature?

Answer 46

Because it can be described as both a wave and a particle

Question 47

What are photons?

Answer 47

When electromagnetic radiation is absorbed or emitted by matter it behaves like a stream of particles. These particles are known as photons

Question 48

What can be used to identify an element?

Answer 48

It’s characteristic emission and absorption spectra

Question 49

How can the discrete lines observed in atomic spectra be explained?

Answer 49

If electrons, like photons also display the properties of both particles and waves

Question 50

What shape are S orbitals?

Answer 50

Spherical

Question 51

What 2 elements are not transition metals when they would be expected to be and why?

Answer 51

Zinc and scandium, they are not transition metals as they do no form a stable lot

Question 52

What can be said about compounds of the same transition metal in different oxidation states?

Answer 52

They may have different colours

Question 53

What is a transition metal complex?

Answer 53

A compound made of a transition metal ion covalently bonded to ligands

Question 54

What is the spectrochemical series?

Answer 54

The order that ligands can be placed in based on their ability to split d orbitals

Question 55

What are the 3 main indicators of a transition metal?

Answer 55

1. Can produce ions with different valencies 2. Make coloured compounds 3. Have catalytic uses