Download 1B Practice Final Ch 12, 13

1B Practice Final
Ch 12, 13
1. Calculate the deBroglie wavelength for the following:
a. an electron whose velocity is 15 % the speed of light
b. a 1.5 kg baseball thrown at 20 m/s
2. Calculate the wavelength associated with the following transition in a hydrogen atom. State
whether it corresponds to an absorption or emission.
a. n = 5 → n = 3
b. ground state → first excited state
3. What is the maximum wavelength of light that can remove an electron from:
a. the first excited state of a hydrogen atom
b. the ground state of a He+ ion
4. The Balmer series of emission lines for hydrogen correspond to transitions in which nf = 2.
What is the longest wavelength in this series?
5. Which of the following sets of quantum numbers are incorrect? State what is wrong.
a. n = 3, l = 2, ml = 0, ms = 1/2
b. n = 2, l = 2, ml = -1, ms = -1/2
c. n = 2, l = 1, ml = -2, ms = 1/2
d. n = 7, l = 6, ml = -6, ms = 1
e. n = 5, l = -4, ml = 4, ms = -1/2
6. How many electrons can have the designation?
a. 5p
b. n = 4
c. 3px
d. 4f
e. 2d
f. 7dxz
7. Draw representations of the following orbitals and determine where any nodes exist:
a. 1s
b. 2s
c. 2py
d. 3s
e. 3pz
8. Write the electron configuration and determine how many unpaired electrons:
a. Te
b. Co
c. Sbd. W
9. Put the following in the correct order of:
a. increasing size
Ca
Cs Se
S
b. decreasing size
Na+ Mg2+ Ne Fc. increasing ionization energy
C
N
O
F
+
2+
3+
d.decreasing ionization energy
Si Si
Si
e.decreasing electron affinity
S
Se Te Cl
f. increasing electronegativity
Rb
As
N
Ca
g. most polar bond
B-F B-Cl
B-Br
h. most covalent bond
H-H O-H N-H
i. largest dipole moment (μ)
CO2 CO NO
j. most exothermic lattice energy NaF
LiF MgO
10. Calculate the lattice energy of MgO based on the following data:
Mg(g) → Mg(s)
MgO(s) → Mg(s) + 1/2O2(g)
Mg(g) → Mg2+(g) + 2e2O(g) → O2(g)
O(g) + 2e- → O2- (g)
-150 kJ
602 kJ
2180 kJ
-494 kJ
737 kJ
11. Use the following information to estimate the bond energy for a nitrogen-nitrogen triple
bond.
N2(g) + 3H2(g) → 2NH3(g)
ΔH = -109 kJ
Bond type
H-H
N-H
bond energy (kJ/mole)
432
391
12. Draw Lewis structures for the following. Show resonance where applicable.
a. H2O b. NCl3
c. BF3
d. CO2
e. SO2
f. CO32g. SCl6
13. For the following, draw two Lewis structures, one which satisfies the octet rule and one
which minimizes formal charge:
a. SO42b. ClO314. Order the following species with respect to the carbon-oxygen bond length (shortest to
longest):
CO, CO2, CO32-, CH3OH
What is the order from weakest to strongest carbon-oxygen bond?
15. Use the following information to estimate the bond energy for a nitrogen-nitrogen triple
bond.
N2(g) + 3H2(g) → 2NH3(g)
ΔH = -109 kJ
Bond type
bond energy (kJ/mole)
H-H
432
N-H
391
16. Give the molecular geometry, polarity and bond angles for:
a. CH4
b. NH3
c. SO2
d. I3e. BrF5