CHEM 121 General Chemistry and Laboratory I Practice Exam Package actual questions with
answers key 2025 Simon Fraser University
Chemistry 121/111 Practice Exam
Package
1. This package was put together by students with knowledge of course content
in CHEM 121 (these exam packs are not affiliated with the courses).
2. We are not guaranteeing that the answers are 100% correct. Please consult
the UCS, should any questions regarding the content of this packet arise.
3. We apologize in advance for errors.
4. Please do not ask professors for questions on these exam packs.
5. NO REFUNDS.
6. If you have any questions please send an email to
7. Please do not copy or reproduce any content from this package without
permission.
,1) A lamp emits light at a wavelength of 550 nm.
a. What is the frequency of this light?
b. What is the colour of this light?
c. What is the energy of a single photon in this wavelength of light?
2) How many photons of light with a frequency of 3.75 GHz are required to produce 2
joules of energy?
3) The binding energy of a particular metal is 373 kJ/mol.
a. What is the lowest frequencies of light that will remove electrons from this
metal?
b. If the metal is irradiated with light of wavelength 170 nm, what is the kinetic
energy of the resulting ionized electrons?
c. If the wavelength is increased to 250 nm, what happens to the kinetic energy
of the resulting ionized electrons?
,4) Rank the following in order of increasing boiling point and explain the reasoning
behind your ranking scheme: 𝐶𝐻4, 𝑁𝑎𝐹, 𝐶𝐻3𝑂𝐻, 𝐶𝐻3𝐹
5) Identify the following orbitals by name and draw the orbital.
a. An orbital with 1 radial node and 1 angular node.
b. An orbital with 0 radial nodes and 2 angular nodes.
c. An orbital with 2 radial nodes and no angular nodes.
6) For a hydrogen atom, the wave function for the state 𝑛 = 2, 𝑙 = 0, 𝑚 = 𝑚𝑖 = 0 can
be described by the following equation:
3/2
Ψ200 = 1 4 1 5 (2 − 𝜎)𝑒−σ/2
4√2𝜋 𝑎 0
where σ = 𝑟/𝑎0 and 𝑎0 is the Bohr radius (5.29E-11 m).
a. What orbital does this wave function describe?
b. Give the definition of a node in a wavefunction.
, c. How many nodes does this wave function have?
d. Using the formula above, calculate the position, in m, of the nodes for this
wavefunction. Hint: The location of the node is given by the term r.
e. Using the axes provided below, sketch the radial probability distribution for
this wavefunction. Label the axes and indicate the point that corresponds to
the most probable distance of the electron from the nucleus.
7) Answer the following questions:
a. How many radial nodes are in an 8s orbital?
b. How many radial nodes are there in a 4d orbital?
c. How many radial nodes are there in a 5p orbital?
answers key 2025 Simon Fraser University
Chemistry 121/111 Practice Exam
Package
1. This package was put together by students with knowledge of course content
in CHEM 121 (these exam packs are not affiliated with the courses).
2. We are not guaranteeing that the answers are 100% correct. Please consult
the UCS, should any questions regarding the content of this packet arise.
3. We apologize in advance for errors.
4. Please do not ask professors for questions on these exam packs.
5. NO REFUNDS.
6. If you have any questions please send an email to
7. Please do not copy or reproduce any content from this package without
permission.
,1) A lamp emits light at a wavelength of 550 nm.
a. What is the frequency of this light?
b. What is the colour of this light?
c. What is the energy of a single photon in this wavelength of light?
2) How many photons of light with a frequency of 3.75 GHz are required to produce 2
joules of energy?
3) The binding energy of a particular metal is 373 kJ/mol.
a. What is the lowest frequencies of light that will remove electrons from this
metal?
b. If the metal is irradiated with light of wavelength 170 nm, what is the kinetic
energy of the resulting ionized electrons?
c. If the wavelength is increased to 250 nm, what happens to the kinetic energy
of the resulting ionized electrons?
,4) Rank the following in order of increasing boiling point and explain the reasoning
behind your ranking scheme: 𝐶𝐻4, 𝑁𝑎𝐹, 𝐶𝐻3𝑂𝐻, 𝐶𝐻3𝐹
5) Identify the following orbitals by name and draw the orbital.
a. An orbital with 1 radial node and 1 angular node.
b. An orbital with 0 radial nodes and 2 angular nodes.
c. An orbital with 2 radial nodes and no angular nodes.
6) For a hydrogen atom, the wave function for the state 𝑛 = 2, 𝑙 = 0, 𝑚 = 𝑚𝑖 = 0 can
be described by the following equation:
3/2
Ψ200 = 1 4 1 5 (2 − 𝜎)𝑒−σ/2
4√2𝜋 𝑎 0
where σ = 𝑟/𝑎0 and 𝑎0 is the Bohr radius (5.29E-11 m).
a. What orbital does this wave function describe?
b. Give the definition of a node in a wavefunction.
, c. How many nodes does this wave function have?
d. Using the formula above, calculate the position, in m, of the nodes for this
wavefunction. Hint: The location of the node is given by the term r.
e. Using the axes provided below, sketch the radial probability distribution for
this wavefunction. Label the axes and indicate the point that corresponds to
the most probable distance of the electron from the nucleus.
7) Answer the following questions:
a. How many radial nodes are in an 8s orbital?
b. How many radial nodes are there in a 4d orbital?
c. How many radial nodes are there in a 5p orbital?
