A methane molecule is composed of one carbon atom and four hydrogen atoms... A the distance between any two pairs of electrons.. 17 A triple bond involves the sharing of ________ pairs o
Trang 1Test Bank for Fundamentals of General Organic and Biological
Chemistry 7th Edition by McMurry
Trang 24) Which representation of a methane molecule is not correct? (A methane
molecule is composed of one carbon atom and four hydrogen atoms.)
Trang 36) In a covalent compound the bond length can be defined as
1 A) the distance between any two pairs of electrons
2 B) the distance between the two largest atoms
3 C) the distance between two nuclei when the repulsion is greatest
4 D) the distance between two nuclei when the attraction is greatest
5 E) the distance between two nuclei when repulsion and attraction are balanced
1 A) nitrogen; sulfur, bromine
2 B) helium; neon, argon
3 C) nitrogen; oxygen, fluorine
4 D) hydrogen; lithium, sodium
5 E) oxygen; phosphorus, germanium
Answer: C
Diff: 2
Section: 4.2
Trang 4
8) A chemical bond formed when two atoms share one pair of electrons is a bond; it is best described as
Trang 717) A triple bond involves the sharing of pairs of electrons between the atoms
Trang 923) Which property could describe a covalent compound?
1 A) It conducts electricity when melted
2 B) It is a gas at room temperature
3 C) It is composed of a non-metal and a metal
4 D) It conducts electricity when dissolved in water
5 E) none of the above
2 Has a definite crystal structure
III Dissolves in water, but not in organic liquids
1 Melts at 80 degrees Celsius
2 Does not conduct electricity when melted
3 A) I, II, III
4 B) I, III, V
5 C) II, III, IV
Trang 1025) Which property is most closely associated with covalent molecules?
1 A) It is a gas at room temperature
2 B) It conducts electricity when dissolved in water
3 C) It has a very high melting point
4 D) It is composed of a metal and a nonmetal
Trang 1230) The number of valence electrons in the acetic acid molecule (CH3CO2H) is
pairs on one or more atoms Note that both of these include pairs of electrons Also
most of these atoms obey the octet rule, which means that each atom has eight electrons in its outer shell The most common exception to the octet rule is
hydrogen, which usually has two electrons Note again that these numbers are all
even numbers
Trang 151 A) bent; two; two
2 B) linear; two; two
3 C) pyramidal; three; one
4 D) tetrahedral; four; zero
5 E) planar triangular; three; one
Trang 1642) The bond angle in the molecule H2S is because the
109 A) exactly 109.5°; S atom has four charge clouds
110 B) greater than 109.5°; lone pairs allow the bond angle to expand
111 C) less than 109.5°; lone pairs force the hydrogen atoms closer
together
112 D) exactly 120°; lone pairs are counted as one charge cloud
113 E) exactly 180°; the S atom has two bonds
Trang 1846) A section of the Periodic Table containing main group elements is shown
Which bond would be least polar?
1 A) WY
2 B) WZ
3 C) XY
Trang 2051) Consider the molecule SiCl4 The electronegativity values for Si and Cl are 1.8 and 3.0, respectively Based on these values and on consideration of molecular
geometry, the Si-Cl bond is and the molecule is
respectively Based on these values and on consideration of molecular
geometry, the HSe bond can be considered almost and the molecule is
1 A) polar; polar
Trang 211 A) the number of atoms bonded to the atom of interest 2 B) the total number
of atoms in the molecule
3 C) the number of electron pairs on the atom of interest
1 A) nonpolar if the geometry is planar triangular
2 B) polar in all cases
3 C) nonpolar in all cases
4 D) impossible to tell the polarity
5 E) either polar or nonpolar depending on the identity of the atoms bonded to the central atom
Answer: A
Diff: 3
Section: 4.10
Trang 22
56) Explain how it is possible for CCl4 to have polar bonds but be a non-polar
molecule A diagram may be helpful in your answer, but it must be explained
Answer: (This question could also be asked about CF4 or CO2.)
The bonds in this compound are polar due to the difference in their
electronegativity values However, the molecule is not polar because the molecule is symmetrical, which means that the polar forces in different directions balance each other out In this case, the overall distribution of electrons in the molecule is even Diff: 2
Trang 2463) The compound BrF3 would be called
1 A) boron trifluoride 2 B) triboron fluoride
3 C) tri (bromine fluoride)
Trang 25Section: 4.10
65) oxygen difluoride Diff: 1
Section: 4.10
1 C) CCI4
66) dinitrogen tetroxide Diff: 1
Section: 4.10
67) bromine pentafluoride
Trang 26Section: 4.10
70) phosphorus trichloride Diff: 1
Section: 4.10
71) carbon monoxide Diff: 1
Section: 4.10
72) sulfur hexafluoride Diff: 1
Section: 4.10
73) sulfur dioxide
Diff: 1