TINA AKINYI
CHEM 177 EXAM REVIEW
10/25/15
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1.
A.
B.
C.
D.
For which reaction is ∆Hrxn0 equal to ∆Hf0 for CuSO4(s)?
Cu2+ (aq) + SO4 2- (aq) → CuSO4(s)
CuO(s) + SO3(g) → CuSO4(s)
CuS(s) + 2O2(g) → CuSO4(s)
Cu(s) + S(s) + 2O2(g) → CuSO4(s)
2. What is the value of ∆H ̊ (in kJ) for this reaction?
2CuO(s) → Cu2O(s) + ½O2(g)
Where Hf 0 CuO = -156.1
And Hf 0 Cu2O = -170.1
3. C2H5OH(l) + 3 O2(g) 2 CO2(g) + 3 H2O(g)
During an experiment 10.00 g of ethanol is completely burned in air to release CO2(g) and H2O(g) as shown
in the equation above. During the combustion, 296.6 kJ of heat energy is released. What is the molar
enthalpy of combustion, H ̊comb?
A. –2966 kJ•mol–1
B. –1366 kJ•mol–1
C. –64.36 kJ•mol–1
D. –29.66 kJ•mol–1
4. For which of the reactions below is (are) the heat of reaction equal to the heat of formation?
I.
½ N2(g) + O2(g) NO2 (g)
∆H rxn > 0
II.
SO2(g) + ½ O2(g)SO3(g)
∆H rxn< 0
A. I. Only
B. II. Only
C. Both I. and II.
D. Neither I nor II
5. Given chemical equations for these reactions
 S(s) + O2(g) SO2 (g)
∆H = –296.8 kJ•mol–1
 H2(g) + ½ O2(g) H2O(l) ∆H = –285.8 kJ•mol–1
 H2(g) + S(s) H2S(g)
∆H= –20.6 kJ•mol–1
What is the value of ∆H rxn for the reaction below?
2H2S(g) + 3O2(g) 2H2O(l) + 2SO2(g)
A. –603.2 kJ•mol–1
B. –562.0 kJ•mol–1
C. –1206.4 kJ•mol–1
D. –1124.0 kJ•mol–1
6.
Find the ΔH rxn for the reaction below, given the subsequent reactions and their ΔH rxn values:
1/2H2(g) + 1/2Cl2(g) → HCl(g)



COCl2(g) + H2O(l) → CH2Cl2(l) + O2(g)
2HCl(g) + 1/2O2(g) → H2O(l) + Cl2(g)
CH2Cl2(l) + H2(g) + 3/2O 2(g) → COCl2(g) + 2H 2O(l)
ΔH = 47.5 kJ
ΔH = 105 kJ
ΔH = -402.5 kJ
A. -230 kJ
B. -460 kJ
C. -115 kJ
D. -116.3 kJ
7.
A.
B.
C.
Calculate the frequency of light that corresponds to the following wavelengths in a vacuum.
12 km
45 pm
700 nm
8.
A.
B.
C.
. Calculate the energy of photons of the following types
423 GHz
12 cm
350 nm
9. What is wavelength of a neutron (m = 1.67 E-27 kg) traveling at a speed of C/500 through a vacuum?
(C= 3.00 E 8 m·s-1)
10. For which of the following transitions would a Hydrogen atom absorb a photon with the longest
wavelength?
A. n=1 to n=2
B. n=3 to n=2
C. n=5 to n=6
D. n=7 to n=6
11. How much energy and would be released if a Hydrogen electron transitioned from the n=4 to the n=3
energy level?
A. 2.043 E-18 J
B. 3.981 E-18 J
C. 1.958 E- 18 J
D. 1.050 E-19 J
12. Which quantum numbers represent the orbitals being filled in the ground state for the elements Sc (21)
to Zn (30)?
A. n= 3, 1= 1
B. n= 3, l= 2
C. n= 4, l= l
D. n= 4, l= 2
13. Which must represent an atom in an excited state?
A. 1s22s22p1
B. 1s22s22p2
C. 1s22s22p23s1
D. 1s22s22p5
14. What is the ground state electron configuration of a 27Co atom in the gas phase?
A. 1s22s22p63s23p63d7
B. 1s22s22p63s23p63d9
C. 1s22s22p63s23p63d84s1
D. 1s22s22p63s23p63d74s2
15. How many orbitals have the quantum numbers: n = 4, l= 3, ml= 0
A. 7
B. 3
C. 1
D. 0
16. Which set of quantum numbers (n, l, ml, ms) is not permitted by the rules of quantum mechanics?
A. 1, 0, 0, ½
B. 2, 1, –1, - ½
C. 3, 3, 1, – ½
D. 4, 3, 2, ½
17. What is the maximum number of electrons that occupy the n = 3 level?
A. 6
B. 8
C. 10
D. 18
18. Write the noble gas electron configuration for each of these atoms and indicate how many valence,
unpaired and core electrons there are in each.
A. Fe
B. Ge
C. Ir
D. Ti
E. S2F. Ag
G. Cr 3+
H. Sn 2+
19. The spheres below represent atoms of P, Sb, N, As, and Bi (not necessarily in that order)
Which one of these spheres represents an atom of Sb?
a. A
20.
b) B
c) C
b) CaS, MgO, KCl, NaF
d) KCl, NaF, CaS, MgO
An atom of which element has the highest second ionization energy?
a. Na
22.
e) E
When NaF , MgO, KCl and CaS are listed in order of increasing lattice energy, which order is correct?
a) MgO, NaF, KCl, CaS
c) KCl, CaS, NaF, MgO
21.
d) D
b) Mg
c) Al
d)K
e) Li
An element M reacts with nitrogen to form M3N2 and with water to form a hydroxide that is
slightly soluble. The mostly likely candidate for the element M is
a. Lithium
b) Calcium
c) Aluminum
d) Silicon
e) Cesium
23. Which species does NOT have an octet of electrons for its outer shell?
a. Mg+
b) P3-
c) O2-
d) C4-
e) Al3+
24. Which of the following element is expected to have large negative electron affinity?
a. O
b) Rb
c) B
d) C
e) Li
25. The electronegativity of A is 2.1 and of B is 0.3.Given that B is a metal , AB4 would be
expected to be
.
a.
b.
c.
d.
e.
be ionic and contain B- ions.
be ionic and contain B+ ions.
have polar covalent bonds with partial positive charge on the B atoms.
have polar covalent bonds with partial negative charge on the B atoms.
have polar covalent bonds with partial negative charge on the A atoms.
26. Arrange the following in order of increasing ionic character:
CsBr
a.
b.
c.
d.
e.
LaBr3
PBr3
CsBr < LaBr3 < MgBr2 < PBr3
CsBr < MgBr2 < PBr3 < LaBr3
PBr < MgBr < LaBr < CsBr3
PBr3 < LaBr3 < MgBr2 < CsBr
CsBr3 < MgBr2 < LaBr3 < PBr3
MgBr2
Element
Bromine
Phosphorus
Magnesium
Lanthanum
Cesium
Electronegativity
2.8
2.1
1.2
1.0
0.7
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