MOCK TEST
1. If the ∆H° for the reaction, 2 Mg (s) + 2 Cl2 (g) → 2 MgCl2 (s), is -1283.6 kJ, what is
the standard enthalpy of formation of magnesium chloride?
A) 0 kJ/mol
B) -320.9 kJ/mol
C) -641.8 kJ/mol
D) 1283.6 kJ/mol
E) -1283.6 kJ/mol
2. Which of the following choices is false regarding the wave amplitude of
electromagnetic radiation?
(Circle all that apply. There may be more than one answer)
A) For visible light, a larger wave amplitude correlates with a brighter light
B) A larger wave amplitude correlates with higher energy photons
C) A larger wave amplitude correlates with a larger number of photons
D) A larger wave amplitude correlates with a longer wavelength
E) A larger wave amplitude correlates with increased wave speed
3. Assign the proper oxidation state for the sulfur atom in each of the following species.
a) H2S
_________
b) Na2SO4
_________
4. Complete combustion of 1.00 mol of acetone (C3H6O) liberates 1790. kJ of heat (the
reaction is shown
below). Given that ΔH°f (CO2) = –393.5 kJ/mol and ΔH°f (H2O) = –285.8 kJ/mol, calculate
the standard
enthalpy of formation of acetone. Make sure to balance the reaction!
C3H6O (l) + O2 (g) → H2O (l) + CO2 (g)
5. 550 nm electromagnetic radiation is in what region of the electromagnetic spectrum?
A) Ultraviolet
B) Visible
C) Infrared
D) Microwave
E) X-ray
6. What volume of 10.0 M H2SO4 is required to prepare 4.0 L of 0.50 M H2SO4?
A) 0.20 L
B) 0.40 L
C) 0.50 L
D) 1.0 L
E) 4.0 L
7. A solution of silver nitrate is mixed with a solution of potassium fluoride. If a
precipitate forms, the precipitate is:
A) Silver fluoride
B) Potassium nitrate
C) Potassium fluorate
D) Nitric fluoride
E) No precipitate is formed
8. If 5.0 mol of both hydrochloric acid and sodium sulfide are mixed and reacted
according to the equation below, how many moles of hydrogen sulfide (H2S) are
produced?
HCl + Na2S -> H2S + NaCl
A) 1 mol
B)
1.25 mol
C)
2.5 mol
D) 3 mol
E) 5 mol
9. Which of the following is not a physical process?
A) distillation B) filtration C) chromatography D) evaporation E) none of the above
10. Of the choices below, which one is not an ionic compound?
A) PCl5 B) MoCl6 C) RbCl D) PbCl2 E) NaCl
11. Boron has two naturally occurring isotopes, 10B with an atomic mass of 10.0129370
amu and 11B with an atomic mass of 11.0093054 amu. The atomic mass of boron is
10.81 (from the periodic table). The percent abundances of the boron isotopes are
__________% 10B and __________% 11 B.
A) 81.0, 19.0
B) 9.9, 90.1
C) 49.0, 51.0
D) 20.0, 80.0
E) 1.0, 99.0
12. Selenium, an element used in the manufacture of solar energy devices, forms an oxide
that contains only one atom of selenium (per formula unit) and is 37.8% oxygen by
mass. What is the molecular formula of the oxide?
13. Solid sulfur and oxygen gas react to produce sulfur trioxide as shown below. In a
particular experiment, 5.0 g of O2 are reacted with 6.0 g of S8. S8 (s) + O2 (g) →
SO3 (g)
a) If we assume complete consumption of the limiting reactant, what is the mass and identity
of the reactant that still remains at the end of the reaction?
b) What is the % yield of SO3 in this experiment if 7.9 g of SO3 are isolated?
14. An iron nail is suspended on a thin wire in a sealed jar of moist air. The surface of the
nail becomes red over time.
a) Describe what is happening to the mass of the nail over time.
b) List the chemical changes taking place in the jar.
15. Choose the incorrect statement:
A. In an anion p < e
B. Atoms of different elements have different numbers of electrons.
C. Bromine-87 has 87 nucleons.
D. The atomic mass of iron is 55.85 which means iron atoms weigh 55.85amu each.
16. What was the order of discovery from earliest to latest of the 3 subatomic particles:
A. e - p - n
B. e - n - p
17. An element X has 3 isotopes with the following mass and abundance:
mass (amu)
abundance
Isotope 1
56.02
50%
Isotope 2
58.08
20%
Isotope 3
61.12
30%
What is the atomic mass of X in amu?
Type your result in the answer, only the number, nothing else, and round off to 2 decimal
place, i.e., 2 numbers after the decimal point.
18. Below are the wavelengths of some types of radiomagnetic radiation:
CO2 laser: 10600 nm
Microwave: 1000000 nm
Gamma ray: 0.01 nm
Green light: 500 nm.
Which one has the highest frequency?
A. Green light
B. CO2 laser
C. Microwave
D. Gamma ray
19. To undergo photoelectric effect, a metal requires an electromagnetic radiation with
wavelength of 26nm. What is the energy of this radiation in J?
20. The energy levels of an electron in a hypothetical atom is shown below:
n = 5, E = -5.20x10^-21 J
n = 4, E = -1.35x10^-21 J
n = 3, E = -8.66x10^-20 J
n = 2, E = -3.28x10^-20 J
n =1, E = -6.75x10^-19 J
When an electron move from a higher level back to n=1, energy is released as a photon with
wavelength of 338nm. What is this higher level?
21. How many p orbitals can an element in 4th period have?
22. Rank the following elements in first ionization energy (IE1), from lowest to highest:
A. Be < Al < Mg < In
B. In < Mg < Al < Be
C. In < Al < Mg < Be
D. Be < Mg < Al < In
23. Rank the following atoms in ionization energy (energy to remove 1 electron), from lowest
to highest: Ca, Ar, K+, Sr
24. The mass of the 3 sub-atomic particles are provided below:
Particle
mass (amu)
p
1.00728
n
1.00866
e
0.00055
Knowing that the experimentally determined mass of nitrogen-16 atom is 16.00610 amu,
what is it binding energy in MeV? (only type a number, round off to 2 decimal places; don't
type anything else).
c = 2.998 x 10^8 m/s
1 amu = 1.66 x 10^-27 kg
1 J = 6.24 x 10^12 MeV
25. Consider the following nuclear fission reaction and the mass of the related particles:
particle
mass (amu)
n
1.00866
U-235
235.04393
Br-87
86.92071
La-146
145.92579
What is the energy released in this reaction in MeV? Type only a number, round off to 2
decimal place; don't type anything else.
c = 2.998 x 10^8 m/s
1 amu = 1.66 x 10^-27 kg
1 J = 6.24 x 10^12 MeV
26. What types of bond are present in the compound Ca(NO3)2?
27. Write resonance forms that describe the distribution of electrons in each of these
molecules or ions.
(a) selenium dioxide, OSeO
(b) nitrate ion, NO3-
(c) nitric acid, HNO3 (N is bonded to an OH group and two O atoms)
(d) benzene, C6H6
(e) the formate ion
(f) sulfur dioxide, SO2
(g) carbonate ion, CO3 2−
(h) pyridine
(i) ) the allyl ion
28. Write the resonance forms of ozone, O3, the component of the upper atmosphere that
protects the Earth from ultraviolet radiation.
29. Determine the formal charge of each element in the following:
(a) H3O+
(b) SO42−
(c) NH3
(d) O22−
(e) H2O2
30. Based on formal charge considerations, which of the following would likely be the
correct arrangement of
atoms in hypochlorous acid: HOCl or OClH?
31. Based on formal charge considerations, which of the following would likely be the
correct arrangement of atoms in sulfur dioxide: OSO or SOO?
32. Write the Lewis structure and chemical formula of the compound with a molar mass of
about 70 g/mol that contains 19.7% nitrogen and 80.3% fluorine by mass, and determine the
formal charge of the atoms in this compound.
33. Which of the following structures would we expect for nitrous acid? Determine the
formal charges:
34. Sulfuric acid is the industrial chemical produced in the greatest quantity worldwide.
About 90 billion pounds are produced each year in the United States alone. Write the Lewis
structure for sulfuric acid, H2SO4, which has two oxygen atoms and two OH groups bonded
to the sulfur
35. Which compound in each of the following pairs has the larger lattice energy? Note: Mg2+
and Li+ have similar radii; O2– and F– have similar radii. Explain your choices.
(a) MgO or MgSe
(b) LiF or MgO
(c) Li2O or LiCl
(d) Li2Se or MgO
36. Which of the following compounds requires the most energy to convert one mole of the
solid into separate ions?
(a) MgO
(b) SrO
(c) KF
(d) CsF
(e) MgF2
37. Explain why the HOH molecule is bent, whereas the HBeH molecule is linear.
38. What feature of a Lewis structure can be used to tell if a molecule’s (or ion’s)
electron-pair geometry and molecular structure will be identical?
39. Why is the H–N–H angle in NH3 smaller than the H–C–H bond angle in CH4? Why is
the H–N–H angle in NH4+ identical to the H–C–H bond angle in CH4?
40. Predict the electron pair geometry and the molecular structure of each of the following
molecules or ions:
(a) SF6
(b) PCl5
(c) BeH2
(d) CH3+
41. Predict the electron pair geometry and the molecular structure of each of the following:
(a) IOF5 (I is the central atom)
(b) POCl3 (P is the central atom)
(c) Cl2SeO (Se is the central atom)
(d) ClSO+ (S is the central atom)
(e) F2SO (S is the central atom)
(f) NO2−
(g) SiO44−
42. The molecule XCl2 has a dipole moment. Is X beryllium or sulfur?
43. Draw the Lewis electron dot structures for these molecules, including resonance
structures where appropriate:
(a) CS32−
(b) CS2
(c) CS
(d) predict the molecular shapes for CS32− and CS2 and explain how you arrived at your
predictions
44. Use valence bond theory to explain the bonding in O2, F2, HF, and ClBr. Sketch the
overlap of the atomic orbitals involved in the bonds
45. Methionine, CH3SCH2CH2CH(NH2)CO2H, is an amino acid found in proteins. Draw a
Lewis structure of this compound. What is the hybridization type of each carbon, oxygen, the
nitrogen, and the sulfur?
46. Two important industrial chemicals, ethene, C2H4, and propene, C3H6, are produced by
the steam (or thermal)
cracking process:
2C3 H8(g) ⟶ C2 H4(g) + C3 H6(g) + CH4(g) + H2(g)
For each of the four carbon compounds, do the following:
(a) Draw a Lewis structure.
(b) Predict the geometry about the carbon atom.
(c) Determine the hybridization of each type of carbon atom
47. For the carbonate ion, CO32−, draw all of the resonance structures. Identify which orbitals
overlap to create each bond.
48. For the molecule allene, H2C = C = CH2, give the hybridization of each carbon atom.
Will the hydrogen atoms be in the same plane or perpendicular planes?
49. For each of the following structures, determine the hybridization requested and whether
the electrons will be
delocalized:
(a) Hybridization of each carbon
(b) Hybridization of sulfur