CEM 141 Final Exam-Question with Correct Answers/ Verified
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Course
Cem 141
Institution
Cem 141
-It is impossible to predict from the information provided, the color of the product does not depend
on the color of the reactant(s) since the properties of the product are emergent -️️A
compound that is red in color reacts with a compound that is yellow in color to make a product. At
room t...
CEM 141 Final Exam-Question with Correct Answers/ Verified
-It is impossible to predict from the information provided, the color of the product does not depend
on the color of the reactant(s) since the properties of the product are emergent - ✔️✔️A
compound that is red in color reacts with a compound that is yellow in color to make a product. At
room temperature, what color will the product be and why?
Energy is absorbed into the system and interactions between the molecules are overcome -
✔️✔️What happens to the system when a molecular substance (such as H2) boils?
When a photon of light is absorbed in a piece of metals, an electron is promoted to a higher energy
molecular orbital within the band. When the electron drops back into the lower energy level, a
photon is emitted - ✔️✔️Which of the following is the best explanation for why metals are shiny?
The melting point of C is higher than that of C60. The covalent bonds in C are stronger and require
more energy to overcome than the LDFs between C60 molecules - ✔️✔️Make a predicition about
the relative melting points of diamond, C, and the molecule buckminsterfullerence c60, then coose
the statement that best explains your prediction
Three sp2 hybrid orbitals on each atom overlap end-to-end while the unhybridized p-orbitals overlap
side-to-side - ✔️✔️According to valence bond therapy, how do bonds form between carbon atoms
in graphite?
Channels of empty space form in the solid state, but not the liquid state, due to hydrogen-bonding
between water molecules - ✔️✔️why is liquid water more dense than solid water (ice)?
Butane contains a larger electron cloud, because butan is more polarizable the molecules have larger
instanteneous dipoles and stronger LDFS, requiring more energy to overcome - ✔️✔️Why does
butane (CH3CH2CH2CH3) have a higher boiling point than ethane (CH3CH3)?
The interference of the light. When a beam of light passes through two small slits the two resulting
waves interfere with each other. Waves of light interfer constructively when they arrive in-phase
and destructively when they arrive out-of-phase causing an interence pattern to emerge. -
✔️✔️Which property of electromagnetic radiation can be explained with the double slit
experiment?
The amplitude of the wave and the number of photons. - ✔️✔️If the INTENSITY of green light is
increased what changes?
, The electron emits a photon when it moves from a higher to a lower energy level. - ✔️✔️What
causes the colored lines that appear on an emission spectrum?
The frequency of the light. Currently the photons do not have enough energy to overcome the
attractive interactions between the elctrons and the nucleus. Increasing this parameter would
increase the energy of each photon. - ✔️✔️Which experimental parameter could you increase to
cause electrons to be ejected from the metals?
Going up from a lower level to a higher level - ✔️✔️How is absorption shown in an energy diagram?
The difference in energy between energy levels are not the same for neon and argon - ✔️✔️Why
are the absoption spectra different for neon and argon?
The wavelength of an electron is similar in size to the electron and therefore affects the properties
of the electron - ✔️✔️Why must we consider the wave-like propertiesof an electron but not a
larger object?
Ca2+ is smaller because it has more protons pulling on the same number of electrons as in S2- -
✔️✔️Do you predict S2- or Ca2+ to have a smaller ionic radius? Why?
Smaller, O has less electrons and therefore has fewer electron-electron repulsions - ✔️✔️Conpare
the oxygen atom, O, and the oxide ion O2-. The radius of O is more _____ than O2-
Between IE 6 and IE 7. This is because it requires more energy to remove a core electron than to
remove a valence electron. - ✔️✔️Where would you predict there to be a big jimp in the successive
ionization energies for oxygen? (You count up the valence electrons, the jump will be 6-7 if the atom
has 6 valence electrons)
Energy is released and a new molecule is formed - ✔️✔️When a covalent bond forms between two
hydrogen atoms
The absorption spectra of galaxies are red-shifted because those galaxies are moving away from us -
✔️✔️Which piece of evidence supports the claim that all matter and energy in the universe were
once concentrated in a single point?
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