Download CHEMONE Directions: Select the letter of the best

CHEMONE
Directions: Select the letter of the best answer. (2 pts each, over 100 only)
1. A 20.92 g sample of an element has the same number of atoms as 12.00g Na. What is the
element?
a. Calcium
b. Tungsten
c. Boron
d. Argon
e. Magnesium
2. Which of the following is an example of a physical property?
a. dynamite explodes
b. toxicity of cyanide
c. meat rots if it is not refrigerated
d. sugar, when heated, becomes brown
e. lead becomes a liquid when heated to 601oC
3. How many molecules of ammonia, NH3, are present in 0.522 moles of ammonia?
a. 5.22 x 10-1
b. 6.26
c. 3.14 x 1023
d. 8.67 x 10-25
e. 1.26 x 1024
4. Which of the following atoms would have the largest second ionization energy?
a. Calcium
b. Sodium
c. Magnesium
d. Chlorine
e. Sulfur
5. Which of the following pairs can be used to illustrate the law of multiple proportions?
a. SO and SO2
b. CO and CaCO3
c. H2O and C12H22O11
d. H2SO4 and H2S
6. Which of the following combinations of quantum numbers is not allowed?
a. n = 1, l = 1, ml = 0, ms = ½
b. n = 3, l = 0, ml = 0, ms = -½
c. n = 2, l = 1, ml = -1, ms = ½
d. n = 4, l = 3, ml = -2, ms = -½
e. n = 4, l = 2, ml = 0, ms = ½
7. Which of the following best describes an orbital?
a. space where electrons are unlikely to be found in an atom
b. space which may contain electron, protons and/or neutrons
c. the space in an atom where an electron is most likely to be found
d. small, walled spheres that contain electrons
e. a single space within an atom that contains all electrons of that atom
8. The statement that “the lowest energy configuration for an atom is the one having the
maximum number of unpaired electrons allowed by the Pauli principle in a particular set of
degenerate orbitals” is known as:
a. Aufbau principle
b. Hund’s rule
c. Heisenberg uncertainty principle
d. Pauli exclusion principle
e. quantum model
9. Which of the following statements is true?
a. The first ionization potential of H is greater than that of He
b. The ionic radius of Fe+ is larger than that of Fe3+
c. The ionization energy of S2- is greater than that of Cld. The atomic radius of Li is larger than that of Cs
10. Which of the following statements from Dalton’s atomic theory is no longer true, according to
modern atomic theory?
a. Atoms are indivisible in chemical reactions
b. Elements are made up of tiny particles called atoms
c. Atoms are not created nor destroyed in chemical reactions
d. All atoms of a given element are identical
e. All of these statements are true according to modern atomic theory
11. If the radius of atom X is greater than the radius of atom Y, then it is also likely that:
a. X has a larger ionization energy than Y does.
b. X is a poorer conductor of electricity than Y when in the solid state.
c. X has a larger electron affinity than Y does.
d. X has a larger effective nuclear charge than Y does.
e. X has greater metallic character than Y does.
12. Which of the following shows the correct electronic configuration?
a. Cu: [Ar] 4s2 3d9
b. Gd: [Xe] 6s2 4f8
c. La: [Xe] 6s2 4f1
d. Cr: [Ar] 4s1 3d5
e. None of the above
13. Rutherford’s experiment with alpha scattering by gold foil established that:
a. atoms are made of protons, neutrons and electrons
b. protons are 1840 times heavier than electrons
c. protons are not evenly distributed throughout an atom
d. electrons have a negative charge
e. electrons have a positive charge
14. The empirical formula of arabinose, a simple sugar, is CH 2O. The molar mass of arabinose is 150
g/mol. What is the molecular formula for this compound?
a. CH10O8
b. C5H2O
c. C4H6O6
d. 5 CH2O
e. C5H10O5
15. An isotope, X, of a particular element has an atomic number of 16 and a mass number of 34.
Thus,
a. X is an isotope of sulfur
b. X has 18 neutrons per atom
c. X has an atomic mass of 32.065
d. A and B
e. A, B, and C
16. You have a sample of zinc (Zn) and a sample of aluminum (Al). You have an equal number of
atoms in each sample. Which of the following statements concerning the masses of the samples
is true?
a. The mass of the Zn sample is more than twice as great as the mass of the Al sample.
b. The mass of the Zn sample is more than the mass of the Al sample, but it is not twice as
great.
c. The mass of the Al sample is more than twice as great as the mass of the Zn sample.
d. The mass of the Al sample is more than the mass of the Zn sample, but it is not twice as
great.
e. The masses of each sample are equal.
17. In which pair do compounds exhibit predominantly ionic bonding?
a. SCl4 and HF
b. Na2SO4 and NH3
c. KI and O3
d. NaF and H2O
e. RbBr and CaO
18. Roundup, a herbicide manufactured by Monsanto, has the formula C3H8NO5P. How many moles
of molecules are there in a 321.0-g sample of Roundup?
a. 0.5267
b. 2.324
c. 1.899
d. 17.83
e. none of the above
19. A hypothetical element consists of two isotopes of masses 84.95 amu and 86.95 amu with
abundances of 37.1% and 62.9% respectively. What is the average atomic mass of this element?
a. 86.2 amu
b. 86.95 amu
c. 85.95 amu
d. 84.95 amu
e. 85.7 amu
20. The molecular structure of SOCl2 is:
a. trigonal planar
b. bent
c. pyramidal
d. octahedral
e. none of these
21. Which of the following groups contains no ionic compounds?
a. NaH, CaF2, NaNH2
b. CH2O, H2S, NH3
c. PCl5, LiBr, Zn(OH)2
d. KOH, CCl4, SF4
22. Which of the following statements is incorrect?
a. Ionic bonding results from the transfer of electrons from one atom to another.
b. Dipole moments result from the unequal distribution of electrons in a molecule.
c. The electrons in a polar bond are found nearer to the more electronegative element.
d. A molecule with very nonpolar bonds can be nonpolar.
e. Linear molecules cannot have a dipole moment.
23. According to VSEPR model, the arrangement of the electron pairs around NH 3 and CH4 is: D
a. different, because in each case there are different number of atoms around the central
atom.
b. different, because in each case there are different number of electron pairs around the
central atom.
c. the same, because both nitrogen and carbon are both in the second period.
d. the same, because in each case there are the same number of electrons around the
central atom.
e. different or the same, depending on the conditions leading to maximum repulsion.
24. Which of the following molecules always has a dipole moment?
a. Linear molecules with two identical bonds.
b. Tetrahedral molecules (four identical bons equally spaced).
c. Trigonal pyramidal molecules (three identical bonds).
d. Trigonal planar molecules (three identical bonds equally spaced).
e. None has a dipole moment.
25. Which of the following pairs is incorrect?
a. iodine trichloride, ICl3
b. phosphorus pentoxide, P2O5
c. ammonia, NH3
d. All of the above pairs are correct.
26. Which of the following species are best described by drawing resonance structures?
a. PH3
b. NH4+
c. O3
d. SO3
e. HCN
27. One molecule of a compound weighs 2.33 x 10-22g. The molar mass of this compound is:
a. 140 g/mol
b. 2.58 g/mol
c. 713 g/mol
d. 132 g/mol
e. none of these
28. What is the correct order of the following bonds in terms of decreasing polarity?
a. N-Cl, P-Cl, As-Cl
b. P-Cl, N-Cl, As-Cl
c. As-Cl, N-Cl, P-Cl
d. P-Cl, As-Cl, N-Cl
e. As-Cl, P-Cl, N-Cl
29. What is the formal charge of P in PBr5?
a. +3
b. -1
c. 0
d. +1
e. +2
30. A sample of ammonia has a mass of 28.5 g. How many molecules are in this sample?
a. 1.67 molecules
b. 1.72 x 1025 molecules
c. 3.60 x 1023 molecules
d. 1.01 x 1024 molecules
e. 5.65 x 10-16 molecules
31. Which of the following is incorrect about ideal gases?
a. At constant amount of gas and temperature, the pressure of the gas is inversely
proportional to its volume.
b. At constant amount of gas and pressure, the volume of the gas is directly proportional to
its temperature.
c. At constant amount of gas and volume, the pressure of the gas is directly proportional to
its temperature.
d. At constant amount of temperature and pressure, the volume of the gas is inversely
proportional to its amount in moles.
e. At constant amount of temperature and volume, the amount of gas in moles is directly
proportional to pressure.
32. Zinc metal is added to hydrochloric acid to generate hydrogen gas, which is collected over a
liquid whose vapour pressure is the same as pure water at 20 oC (18 torr). The volume of the gas
mixture is 1.7 L and its total pressure is 0.810 atm. Determine the partial pressure of the
hydrogen gas in this mixture.
a. 0.786 atm
b. 698 torr
c. 12.4 psi
d. 71000 Pa
33. Atop Mt. Everest, the atmospheric pressure is 210 mmHg and the air density is 0.426 g/L.
Calculate the air temperature, given that the molar mass of air is 29.0 g/mol.
a. 242 K
b. 242oC
c. -41oC
d. 10oF
34. Which of the following statements about liquid is true?
a. Droplet formation occurs because of the higher stability associated with increased
surface area.
b. Substances that can form hydrogen bonds will display low melting points than predicted
from periodic trends.
c. London dispersion forces arise from the distortion of the electron clouds within a
molecule or atom.
d. Liquid rise within a capillary tube because of the small size that lowers the effective
atmospheric pressure over the surface of the liquid
e. The boiling point of a solution is dependent solely on the atmospheric pressure over the
solution.
35. Which one of the following decreases as the strength of the attractive intermolecular forces
increases?
a. heat of vaporization
b. normal boiling temperature
c. the extent of deviations from the ideal gas law
d. sublimation temperature of a solid
e. vapor pressure of a liquid
36. A 0.271 g sample of an unknown vapor occupies 294 mL at 140oC and 847 mmHg. The empirical
formula of the compound is CH2.What is the molecular formula of the compound?
a. CH2
b. C2H4
c. C3H6
d. CH
e. CH4
37. A 1.07 g sample of a noble gas occupies a volume of 363 mL at 35oC and 678 mmHg. Identify the
noble gas in the sample?
a. He
b. Ne
c. Ar
d. Kr
e. Xe
38. Which statement is false?
a. The average kinetic energies of molecules from sample of different “ideal” gases is the
same at the same temperature.
b. The molecules of an ideal gas are relatively far apart.
c. All molecules of an ideal gas have the same kinetic energy at constant temperature.
d. Molecules of a gas undergo many collisions with each other and the container walls.
e. Molecules of greater mass have a lower average speed than those of less mass at the
same temperature.
39. Samples of the following volatile liquids are opened simultaneously at one end of a room. If you
are standing at the opposite end of this room, which species would you smell first? (Assume that
your nose is equally sensitive to all these species.)
a. ethyl acetate (CH3COOC2H5)
b. naphthalene (C10H8)
c. camphor (C10H16O)
d. pentanethiol (C5H11SH)
e. diethyl ether (C2H5OC2H5)
40. 1.000 atm of dry nitrogen, placed in a container having a pinhole opening in its side, leaks from
the container 3.55 times faster than does 1.000 atm of an unknown gas placed in the same
apparatus. Which of these species could be the unknown gas?
a. NH3
b. C4H10
c. SF6
d. UF6
e. Rn
41. Which of the following statements regarding water is true?
a. Energy must be given off in order to break down the crystal lattice of ice to liquid.
b. Hydrogen bonds are stronger than covalent bonds.
c. Liquid water is less dense than solid water.
d. Only covalent bonds are broken when ice melts.
e. All of the statements (A-D) are false.
42. Gases are sold in large cylinders for laboratory use. What pressure, in atmospheres, will be
exerted by 2,500 g of oxygen gas when stored at 22oC in a 40.0 L cylinder?
a. 3.55 atm
b. 1,510 atm
c. 47.3 atm
d. 7.56 x 104 atm
e. 10.2 atm
43. For a substance that remains a gas under the conditions listed, deviation from the ideal gas law
would be most pronounced at:
a. 100oC and 2.0 atm
b. 0oC and 2.0 atm
c. -100oC and 2.0 atm
d. -100oC and 4.0 atm
e. 100oC and 4.0 atm
44. You are given the following boiling point data. Which one of the liquids would you expect to
have the highest vapor pressure at room temperature?
a. water, H2O
b. methanol, CH3OH
c. ethanol, CH3CH2OH
d. diethyl ether, CH3CH2OCH2CH3
e. ethylene glycol, HOCH2CH2OH
45. If equal masses of O2(g) and HBr(g) are in separate containers of equal volume and temperature,
which one of these statements is true?
a. The pressure in the O2 container is greater than that in the HBr container.
b. There are more HBr molecules than O2 molecules.
c. The average velocity of the O2 molecules is less than that of the HBr molecules.
d. The average kinetic energy of HBr molecules is greater than that of O2 molecules.
e. The pressures of both gases are the same.
46. What is the coefficient for water when the following equation is balanced?
𝐴𝑠(𝑂𝐻)3(𝑠) + 𝐻2 𝑆𝑂4(𝑎𝑞) → 𝐴𝑠2 (𝑆𝑂4 )3(𝑎𝑞) + 𝐻2 𝑂(𝑙)
a.
b.
c.
d.
e.
1
2
4
6
12
For numbers 47-49,
Ferrocene, Fe(C5H5)2 (s), can be prepared by reacting 3.0 g of FeCl2 (s) with an equal mass of
cyclopentadiene, C5H6 (l), and an excess of KOH (aq), as shown in the following reaction:
𝐹𝑒𝐶𝑙2(𝑠) + 2𝐶5 𝐻6(𝑙) + 2𝐾𝑂𝐻(𝑎𝑞) → 𝐹𝑒(𝐶5 𝐻5 )2(𝑠) + 2𝐻2 𝑂(𝑙)
47. What is the limiting reagent in this procedure?
a. KOH
b. Fe(C5H5)2
c. FeCl2
d. C5H6
48. Based on your answer in number 4, what mass of Fe(C5H5)2 could theoretically be formed?
a. 2.9 g
b. 4.2 g
c. 5.3 g
d. 1.6 g
49. A student who carried out this reaction obtained 2.7 g of ferrocene. What was the percent yield
for this reaction?
a. 70%
b. 83.1%
c. 64%
d. 76.2%
50. Given the reaction 3𝐴 + 𝐵 → 𝐶 + 𝐷, you react 2 moles of A with 1 mole of B. Which of the
following is true?
a. A is the limiting reactant because of its higher molar mass.
b. A is the limiting reactant because you need 3 moles of A and only have 2.
c. B is the limiting reactant because you have fewer moles of B than A.
d. B is the limiting reactant because 3 A molecules react with 1 B molecule.
e. Neither reactant is limiting.
51. Phosphoric acid can be prepared by reaction of sulfuric acid with “phosphate rock” according to
the equation:
𝐶𝑎3 (𝑃𝑂4 )2 + 3𝐻2 𝑆𝑂4 → 3𝐶𝑎𝑆𝑂4 + 2𝐻3 𝑃𝑂4
Suppose the reaction is carried out starting with 115 g of Ca3(PO4)2 and 84.4 g of H2SO4. Which
substance is the limiting reactant?
a. Ca3(PO4)2
b. H2SO4
c. CaSO4
d. H3PO4
52. When 299.4 g of ethylene (C2H4) burns in oxygen to give carbon dioxide and water, how many
grams of CO2 are formed?
a. 939.4 g
b. 469.7 g
c. 234.9 g
d. 10.67 g
e. 384.6 g
53. A 5.95-g sample of AgNO3 is reacted with BaCl2 according to the equation
2𝐴𝑔𝑁𝑂3(𝑎𝑞) + 𝐵𝑎𝐶𝑙2(𝑎𝑞) → 2𝐴𝑔𝐶𝑙(𝑠) + 𝐵𝑎(𝑁𝑂3 )2(𝑎𝑞)
to give 3.56 g of AgCl. What is the percent yield of AgCl?
a. 50.5%
b. 59.8%
c. 35.5%
d. 70.9%
e. 100%
54. An excess of sodium hydroxide is treated with 25.1 L of dry hydrogen chloride gas measured at
STP. What is the mass of sodium chloride formed?
a. 1.47 kg
b. 1.78 g
c. 0.131 kg
d. 65.5 g
e. 12.6 g
55. A mixture of KCl and KClO3 weighing 1.25 g was heated; the dry O2 generated occupied 143 mL
at STP. What percent of the original mixture was KClO3, which decomposes as follows:
2𝐾𝐶𝑙𝑂3(𝑠) → 2𝐾𝐶𝑙(𝑠) + 3𝑂2(𝑔)
a. 41.7%
b. 62.6%
c. 93.9%
d. 11.4%
e. 25.4%
Answers:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
A
E
C
B
A
A
C
B
B
D
E
D
A
E
D
A
E
C
A
C
B
E
D
C
B
C
A
E
C
D
D
A
C
C
E
B
D
C
E
D
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
E
C
D
D
A
D
D
B
C
B
B
A
D
D
A