Download Practice Exam III

Supplemental Instruction:Chem177
Practice Exam III
April 2, 2009
1. Which of the following is a statement of Hess's law?
A) If a reaction is carried out in a series of steps, the ΔH for the reaction will
equal the sum of the enthalpy changes for the individual steps.
B) If a reaction is carried out in a series of steps, the ΔH for the reaction will
equal the product of the enthalpy changes for the individual steps.
C) The ΔH for a process in the forward direction is equal in magnitude and
opposite in sign to the ΔH for the process in the reverse direction.
D) The ΔH for a process in the forward direction is equal to the ΔH for the
process in the reverse direction.
E) The ΔH of a reaction depends on the physical states of the reactants and
products.
2. Of the following transitions in the Bohr hydrogen atom, the __________
transition results in the emission of the highest-energy photon.
A) n = 1 → n = 6
B) n = 6 → n = 1
C) n = 6 → n = 3
D) n = 3 → n = 6
E) n = 1 → n = 4
3. The n = 1 shell contains __________ p orbitals. All the other shells contain
__________ p orbitals.
A) 3, 6
B) 0, 3
C) 6, 2
D) 3, 3
E) 0, 6
4. [Ar]4s2 3d10 4p3 is the electron configuration of a(n) __________ atom.
A) As
B) V
C) P
D) Sb
E) Sn
5. An electron cannot have the quantum numbers n = __________, l =
__________, ml = __________.
A) 2, 0, 0
B) 2, 1, -1
C) 3, 1, -1
D) 1, 1, 1
E) 3, 2, 1
6. In general, as you go across a period in the periodic table from left to right:
(1) the atomic radius __________;
(2) the electron affinity becomes __________ negative; and
(3) the first ionization energy __________.
A) decreases, decreasingly, increases
B) increases, increasingly, decreases
C) increases, increasingly, increases
D) decreases, increasingly, increases
E) decreases, increasingly, decreases
7. Which of the following is an isoelectronic series?
A) B5- ,Sr 4- ,As3- ,Te2B) F ,Cl ,Br  ,I
C) S, Cl, Ar, K
D) Si 2- ,P2- ,S2- ,Cl 2E) O2- ,F, Ne,Na 
8. In the molecule below, which atom has the largest partial negative charge ?
A) Cl
B) F
C) Br
D) I
E) C
9. Which one of the following configurations depicts an excited oxygen atom?
A) 1s2 2s2 2p2
B) 1s2 2s2 2p2 3s 2
C) 1s2 2s2 2p1
D) 1s2 2s2 2p4
E)  He 2s2 2p4
10. Of the following elements, __________ has the most negative electron affinity.
A) Na
B) Li
C) Be
D) N
E) F
11. Of the following species, __________ has the largest radius.
A) Rb 
B) Sr 2
C) Br 
D) Kr
E) Ar
12. A tin atom has 50 electrons. Electrons in the __________ subshell experience
the lowest effective nuclear charge.
A) 1s
B) 3p
C) 3d
D) 5s
E) 5p
13. Which electron configuration denotes an atom in its ground state?
A)
B)
C)
D)
E)
14. In the Lewis symbol for a fluorine atom, there are __________ paired and
__________ unpaired electrons.
A) 4, 2
B) 4,1
C) 2, 5
D) 6, 1
E) 0, 5
15. Given the electronegativities below, which covalent single bond is most polar?
Element:
H
C
N O
Electronegativity:
2.1
2.5 3.0 3.5
A) C-H
B) N-H
C) O-H
D) O-C
E) O-N
16. Given the data in the table below, H
rxn
for the following reaction is how
many kJ?
4NH3 (g)  5O2 (g)  4NO(g)  6H2O(l)
17. The bond length in an HI molecule is 1.61 Å and the measured dipole moment
is 0.44 D. What is the magnitude (in units of e) of the negative charge on I in
HI?
18. When the electron in a hydrogen atom moves from n = 8 to n = 2 light, what is
the wavelength of light emitted (in nm)?
19. What is the frequency (s1 ) of electromagnetic radiation that has a wavelength
of 0.53 m?
20. What is the wavelength (angstroms) of a photon that has an energy of
4.38  1018 J?
21. Draw the Lewis structure for CH2O.
22. a) Write the complete electron configuration for a stable ion formed by a
calcium atom.
b) Write the complete electron configuration for a stable ion formed by an
oxygen atom.
23. a) Write the balanced equation for the reaction of potassium with water.
b) Write the balanced equation for the reaction of elemental fluorine with
water.
24. The de Broglie wavelength of an electron is 8.7 1011 m . The mass of an
electron is 9.11031 kg . The velocity of this electron is __________ m/s.