CHEM0010 EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
What is the spin of each subatomic particle in an atom?
1/2.
Describe how a mass spectrometer works.
The sample is vaporised and ionised as sprayed into the TOF tube where an electric
field accelerates the ions by the same kinetic energy and a magnetic field then deflects
the particles according to their mass/charge ratio thus meaning that the smaller particles
with lower molecular mass reach the end plate detector first.
What is a wavefunction?
A mathematical description of the distribution of electrons in terms of position and time.
What is the Heisenberg uncertainty principle?
That the position and energy of an electron cannot simultaneously be determined.
What is the principal quantum number?
n = how big the orbital is, or how far an electron occupying it is on average from the
nucleus.
What is the angular momentum quantum number?
l = indicates the shape of the orbital.
What does l=0 or l=1 mean?
l=0 means that it is an s orbital whilst l=1 means it is a p orbital.
What does n=1 or n=2 mean?
,n=1 means that there is only one subshell (1s) whilst n=2 means that there are 2
subshells (2s and 2p).
How many orbitals are in an s, p and d subshell?
There is one s-orbital in an s-subshell whilst there are three p-orbitals and 5 d-orbitals.
What is the magnetic quantum number?
ml = the orientation of the orbital ie px, py or pz.
If l=1 what does ml=-1, 0 or +1 mean?
When l=1, ml=-1 means a px orbital whilst ml=0 means a py orbital and ml=+1 means a
pz orbital.
When does the sign of a wavefunction change?
Either side of a node.
Draw a 2px orbital.
Draw a 2py orbital.
Draw a 2pz orbital.
Draw a dxy orbital.
What is the radial distribution function of an orbital?
How the probability of finding the electron varies with distance from the nucleus.
What is the spin quantum number?
ms=+1/2 (upwards arrow) or -1/2 (downwards arrow).
What is the Pauli exclusion principle?
That no two electrons in an atom can have the same four quantum numbers.
Why do electrons tend to occupy different orbitals with parallel spins?
Parallel spins stay further away from each other and so repulsion is reduced.
, What is a resonance hybrid?
A structure which is an average of the possible resonance forms a molecule could take.
What are hypervalent compounds?
Compounds which require more than an octet of electrons in order to draw the Lewis
structure.
What are the angles and shape of a linear molecule?
Bond angle is 180.
What are the angles and shape of a trigonal planar molecule?
Bond angle is 120.
What are the angles and shape of a tetrahedral molecule?
Bond angle is 109.5.
What are the angles and shape of a trigonal bipyramidal molecule?
Angles are 90 and 120.
What are the angles and shape of an octahedral molecule?
Bond angle is 90.
What are the angles and shape of a pentagonal bipyramidal molecule?
Bond angles are 90 and 72.
If a lone pair has a choice between an equatorial position and an axial position,
which will it occupy?
The equatorial site.
What does it mean that oxygen is paramagnetic?
That it has unpaired electrons.
What is the Valence-bond theory?
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
What is the spin of each subatomic particle in an atom?
1/2.
Describe how a mass spectrometer works.
The sample is vaporised and ionised as sprayed into the TOF tube where an electric
field accelerates the ions by the same kinetic energy and a magnetic field then deflects
the particles according to their mass/charge ratio thus meaning that the smaller particles
with lower molecular mass reach the end plate detector first.
What is a wavefunction?
A mathematical description of the distribution of electrons in terms of position and time.
What is the Heisenberg uncertainty principle?
That the position and energy of an electron cannot simultaneously be determined.
What is the principal quantum number?
n = how big the orbital is, or how far an electron occupying it is on average from the
nucleus.
What is the angular momentum quantum number?
l = indicates the shape of the orbital.
What does l=0 or l=1 mean?
l=0 means that it is an s orbital whilst l=1 means it is a p orbital.
What does n=1 or n=2 mean?
,n=1 means that there is only one subshell (1s) whilst n=2 means that there are 2
subshells (2s and 2p).
How many orbitals are in an s, p and d subshell?
There is one s-orbital in an s-subshell whilst there are three p-orbitals and 5 d-orbitals.
What is the magnetic quantum number?
ml = the orientation of the orbital ie px, py or pz.
If l=1 what does ml=-1, 0 or +1 mean?
When l=1, ml=-1 means a px orbital whilst ml=0 means a py orbital and ml=+1 means a
pz orbital.
When does the sign of a wavefunction change?
Either side of a node.
Draw a 2px orbital.
Draw a 2py orbital.
Draw a 2pz orbital.
Draw a dxy orbital.
What is the radial distribution function of an orbital?
How the probability of finding the electron varies with distance from the nucleus.
What is the spin quantum number?
ms=+1/2 (upwards arrow) or -1/2 (downwards arrow).
What is the Pauli exclusion principle?
That no two electrons in an atom can have the same four quantum numbers.
Why do electrons tend to occupy different orbitals with parallel spins?
Parallel spins stay further away from each other and so repulsion is reduced.
, What is a resonance hybrid?
A structure which is an average of the possible resonance forms a molecule could take.
What are hypervalent compounds?
Compounds which require more than an octet of electrons in order to draw the Lewis
structure.
What are the angles and shape of a linear molecule?
Bond angle is 180.
What are the angles and shape of a trigonal planar molecule?
Bond angle is 120.
What are the angles and shape of a tetrahedral molecule?
Bond angle is 109.5.
What are the angles and shape of a trigonal bipyramidal molecule?
Angles are 90 and 120.
What are the angles and shape of an octahedral molecule?
Bond angle is 90.
What are the angles and shape of a pentagonal bipyramidal molecule?
Bond angles are 90 and 72.
If a lone pair has a choice between an equatorial position and an axial position,
which will it occupy?
The equatorial site.
What does it mean that oxygen is paramagnetic?
That it has unpaired electrons.
What is the Valence-bond theory?
