CHE 105 FA17 Exam 3 Your Name: Your ID: ____________________________________________________________________________ Question #: 1 Octane undergoes combustion to produce heat. This reaction is 1 [endothermic, exothermic]. The sign for ΔH for this process is 2 [positive, negative] 1. 2. ____________________________________________________________________________ Question #: 2 The 1 of conservation of 2 states that the energy is neither created nor destroyed. 1. 2. ____________________________________________________________________________ Question #: 3 Match the frequencies of light below with the corresponding portion the electromagnetic spectrum by filling in each blank with orange, microwave, ultraviolet, or green. Scroll down to see all four frequencies. 5.7×10 14 s –1 1 4.9×10 14 s –1 2 3.2×10 15 s –1 3 6.1×10 9 s –1 4 1. 2. 3. 4.
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CHE 105 FA17 Exam 3 - University of Kentuckychem.as.uky.edu/sites/default/files/GenChemExams/105/2017Fall_105_Ex3.pdf · CHE 105 FA17 Exam 3 ... An argon laser emits radiation at
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Match the frequencies of light below with the corresponding portion the electromagnetic spectrum by filling in each blank with orange, microwave, ultraviolet, or green. Scroll down to see all four frequencies.
How many photons are produced by a laser pulse of 449 mJ at a wavelength of 441 nm? Report your answer with three significant figures. Do NOT include units in your answer. For answers in scientific notation, use the format 2.22E2 for 2.22×102 or 2.22E-2 for 2.22×10–2 1 photons
A metal surface absorbs a photon with a wavelength of 500. nm and ejects an electron with a kinetic energy of 3.40 x10-20 J. Determine its binding energy in joules.
What is the velocity (speed) of a neutron (mass=1.67 ×10-24 g) whose wavelength is 0.155 nm? 1 m/s Report your answer to three significant figures. Do NOT include units in your answer. Use the format 2.22E2 for 2.22×102 or 2.22E-2 for 2.22×10–2.
The principal quantum number is given the symbol 1 , which indicates the distance from the nucleus and the energy of the orbital. The angular momentum quantum is given the symbol l and determines the 2 [energy, shape, orientation] of the orbital. When n=3, the angular momentum quantum number has a minimum value of 3 and a maximum value of 4 .
Calculate the energy of absorbed photons when an electron in a hydrogen atom undergoes a transition from n = 1 to n = 4. Report your answer with three significant digits. Do NOT include units in your answer. For numbers in scientific notation, use the format 2.22E2 for 2.22 × 102 or 2.22E-2 for 2.22 × 10–2 1 J
What are the four quantum numbers for the last electron added to the electron configuration of lithium? Report your answer with numbers separated by commas (1,1,1,1). 1
Arrange the following ions in order of decreasing (largest to smallest) ionic radius. K+, Ca2+, S2–, Cl–. Report your answers as element symbols. 1 > 2 > 3 > 4
A Lewis structure of the carbonate ion (CO32-) includes 1 single bonds, 2 double
bonds, 3 triple bonds. The molecule contains 4 lone pairs of valence electrons. Report each answer as a whole number. Do NOT include units in your answer.
The cyanate ion contains one atom each of carbon, nitrogen and oxygen and has a charge of –1. The best Lewis structure, based on formal charges, contains one single bond and one triple bond. Report each answer as a chemical symbol. The central atom is 1 [C, N, O]. The central atom forms a single bond with 2 [C, N, O] and a triple bond with 3 [C, N, O].
The sign for ΔH for this process is 2 [positive, negative]
1. exothermic
2. negative
Question #: 2
The 1 of conservation of 2 states that the energy is neither created nor destroyed.
1. law
2. energy
Question #: 3
Match the frequencies of light below with the corresponding portion the electromagnetic
spectrum by filling in each blank with orange, microwave, ultraviolet, or green. Scroll
down to see all four frequencies.
5.7×1014 s–1 1
4.9×1014 s–1 2
3.2×1015 s–1 3
6.1×109 s–1 4
1. green
2. orange
3. ultraviolet
4. microwave
Question #: 4
An argon laser emits radiation at a wavelength of 190 nm. Calculate the energy of a mole of
photons at this wavelength in units of kJ/mole.
A. 1.3×10-31
B. 7.9×10-8
C. 6.3×10-4
✓D. 6.3×102
Question #: 5
How many photons are produced by a laser pulse of 449 mJ at a wavelength of 441 nm?
Report your answer with three significant figures. Do NOT include units in your answer. For
answers in scientific notation, use the format 2.22E2 for 2.22×102 or 2.22E-2 for 2.22×10–2
1 photons
1. 9.96e17|9.96E+17|
Question #: 6
A metal surface absorbs a photon with a wavelength of 500. nm and ejects an electron with a kineticenergy of 3.40 x10-20 J. Determine its binding energy in joules.
✓A. 3.64 x 10-19 J B. 3.64 x 10-20 J C. 5.76 x 10-20 J D. 5.76 x 10-19 J
Question #: 7
What is the velocity(speed) of a neutron (mass=1.67 ×10-24 g) whose wavelength is 0.155 nm?
1 m/s
Report your answer to three significant figures. Do NOT include units in your answer. Use the
format 2.22E2 for 2.22×102 or 2.22E-2 for 2.22×10–2.
1. 2.56E3
Question #: 8
The principal quantum number is given the symbol 1 , which indicates the distance from the
nucleus and the energy of the orbital. The angular momentum quantum is given the symbol l
and determines the 2 [energy, shape, orientation] of the orbital. When n=3, the angular
momentum quantum number has a minimum value of 3 and a maximum value of 4 .
1. n
2. shape
3. zero|0|
4. two|2|
Question #: 9
Calculate the energy of absorbed photons when an electron in a hydrogen atom undergoes a
transition from n = 1 to n = 4.
Report your answer with three significant digits. Do NOT include units in your answer. For
numbers in scientific notation, use the format 2.22E2 for 2.22 × 102 or 2.22E-2 for 2.22 × 10–2
1 J
1. 2.04E-18|+2.04E-18|
Question #: 10
Which one is not a possible atomic orbital?
A. 1s B. 2p
✓C. 3f D. 4d
Question #: 11
Give the numerical value of l for the orbitals seen below. Scroll down to see all four images.
Report each answer as a whole number.
l = 1 l= 2
1. 2
2. 0
3. 3
4. 1
Question #: 12
According to _____, no two electrons in the same atom can have the same four quantum
numbers.
A. the Aufbau principle
✓B. the Pauli exclusion principle C. Hund's rule D. the Bohr model
Question #: 13
Identify the element represented by each electron configuration. Report each answer as a
chemical symbol.
1 [Ar]4s23d104p1
2 1s22s22p5
3 [Kr]5s24d1
1. Ga
l= 3 l = 4
2. F
3. Y
Question #: 14
Which element has atoms with exactly four valence electrons in its ground state?
A. Ca B. Cr
✓C. Si D. S
Question #: 15
Which two elements are paramagnetic?
✓A. nitrogen ✓B. lead
C. calcium D. krypton E. zinc
Question #: 16
What are the four quantum numbers for the last electron added to the electron configuration of
lithium?
Report your answer with numbers separated by commas (1,1,1,1).
1
1. 2,0,0,+1/2|2,0,0,-1/2|
Question #: 17
Which one lists the elements from smallest to largest atomic (covalent) radii?
A. Cs <Rb< He <Na <Li B. He <Cs <Rb <Na <Li C. Cs <He <Li <Na <Rb
✓D. He <Li <Na <Rb <Cs
Question #: 18
Arrange the following ions in order of decreasing (largest to smallest) ionic radius. K+, Ca2+,
S2–, Cl–.
Report your answers as element symbols.
1 > 2 > 3 > 4
1. S
2. Cl
3. K
4. Ca
Question #: 19
Which equation represents the process related to the first ionization energy of the element?
A. Cl(g) + e– →Cl– (g) + energy B. Ca+(g) + energy →Ca2+(g) + e–
✓C. Ne(g) + energy →Ne+(g) + e–
D. CaCl2(s) + energy →Ca2+(g) + 2 Cl– (g)
Question #: 20
The second period element, 1 , would experience a large increase between the third
and fourth ionization energies.
1. boron|Boron|B|
Question #: 21
Electron affinity of an atom is the energy associated with the equation:
A. X—(g) →X(g) + e—
✓B. X(g) + e— →X—(g)
C. X(g) →X+(g) + e—
D. X+(g) + e— →X(g)
Question #: 22
How many unpaired electrons are in a gaseous Co3+ ion in its ground state?
A. 0 B. 2
✓C. 4 D. 6
Question #: 23
Which bond is most polar?
A. S-O
✓B. C-F C. C-H D. Cl-Cl
Question #: 24
A Lewis structure of the carbonate ion (CO32-) includes 1 single bonds, 2 double bonds,
3 triple bonds. The molecule contains 4 lone pairs of valence electrons.
Report each answer as a whole number. Do NOT include units in your answer.
1. 2|two|
2. 1|one|
3. 0|zero|
4. 8|eight|
Question #: 25
Which two Lewis structures are examples of exceptions to the octet rule?
✓A.
B.
✓C.
D.
Question #: 26
The cyanate ion contains one atom each of carbon, nitrogen and oxygen and has a charge of –1.
The best Lewis structure, based on formal charges, contains one single bond and one triple bond.
Report each answer as a chemical symbol.
The central atom is 1 [C, N, O].
The central atom forms a single bond with 2 [C, N, O] and a triple bond with 3 [C, N, O].
1. C
2. O
3. N
Question #: 27
Which two compounds have the larger lattice energy listed first?
✓A. MgO, CaS
B. NaCl, MgCl2 ✓C. CaCl2, CaI2
D. CsI, RbI
Question #: 28
Which substance has an electron group geometry of trigonal bipyramidal?
✓A. SF4
B. XeF4 C. CH4 D. XeOF4
Question #: 29
Draw the Lewis structure of SO2. What is the electron group geometry and the molecular