VSEPR Flashcards: Molecular Geometry & Bond Angles
Practice VSEPR shapes, electron geometry, lone pairs, AXE notation, and ideal bond angles with 78 focused English flashcards.
Par šo kavu
Practice VSEPR molecular geometry with 78 English flashcards for high-school and introductory-college chemistry. You should already be able to read simple formulas and Lewis structures. This is focused shape prediction and recall, not a complete chemistry course.
Cards map electron-domain counts to electron geometry; AXE notation to molecular shape and, where lone pairs change the shape, to electron geometry; and selected molecular formulas to shape. Separate prompts retrieve ideal bond-angle benchmarks. A few reverse prompts recover AXE notation from a shape plus its domain count. Contrast and error-diagnosis questions distinguish electron geometry from molecular geometry, count multiple bonds correctly, and show why a shape name alone may not determine the domain count or an exact angle.
The 13 cases are AX₂; AX₃ and AX₂E; AX₄, AX₃E, and AX₂E₂; AX₅, AX₄E, AX₃E₂, and AX₂E₃; and AX₆, AX₅E, and AX₄E₂. Later cards cover axial and equatorial sites, usual lone-pair placements, and ideal versus actual angles. The sequence starts with domains and notation, develops two-to-four-domain cases, then interleaves five- and six-domain cases before final comparisons. Related prompts are separated; the review scheduler handles longer-term spacing.
Practice is text based. Diagram identification, exhaustive Lewis-structure construction, formal charges, polarity, radicals, transition-metal coordination, seven-domain cases, hybridization, and molecular-orbital theory are excluded to keep the deck focused. Shape-to-molecule lists and every possible reverse mapping are omitted because many answers would be valid. Numerical species-angle tables are omitted: ideal benchmarks do not give exact measured angles for every molecule.
All cards carry the VSEPR tag. Original questions, answers, organization, and metadata were prepared with AI assistance and checked against university chemistry references. The cover is an original AI-generated illustration of a generic tetrahedral model; its colors do not identify elements. No source prose, diagrams, competitor cards, or examination questions were copied. Common chemical facts are not claimed as proprietary. Original material, including the generated cover to the extent applicable rights exist, is dedicated under CC0 1.0. This is independent study material, with no university, course, or examination endorsement.
Kartītes šajā kavā
1. kartīte
Jautājums
In VSEPR, what is an electron domain around a central atom?
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A region of electron density: one bond to a neighboring atom, regardless of bond order, or one lone pair.
2. kartīte
Jautājums
What does the VSEPR model use to predict a central atom’s geometry?
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Repulsion between electron domains. The domains favor an arrangement that reduces their mutual repulsion.
3. kartīte
Jautājums
In AXₙEₘ notation, what does A represent?
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The central atom whose local geometry is being described.
4. kartīte
Jautājums
How do electron geometry and molecular geometry differ in VSEPR?
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Electron geometry includes all electron domains. Molecular geometry describes the arrangement of atoms around the central atom, leaving lone pairs out of the shape name.
5. kartīte
Jautājums
How many VSEPR domains does one triple bond contribute at either bonded atom?
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One domain. Three shared electron pairs occupy one bonding direction.
6. kartīte
Jautājums
In AXₙEₘ notation, what does n count?
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Atoms directly bonded to the central atom. A double or triple bond still contributes one X.
7. kartīte
Jautājums
For a molecule with several central atoms, where do you apply VSEPR?
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At each central atom separately, using its own bonded neighbors and lone pairs.
8. kartīte
Jautājums
In AXₙEₘ notation, what does m count?
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Lone pairs on the central atom. E counts pairs, not individual electrons.
9. kartīte
Jautājums
For an AXₙEₘ center in the usual closed-shell VSEPR model, how many electron domains are present?
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n + m domains: bonded neighbors plus lone pairs.
10. kartīte
Jautājums
VSEPR molecular shape of AX₂, with no lone pairs on A?
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Linear. The two bonded atoms lie on opposite sides of the central atom.
11. kartīte
Jautājums
VSEPR molecular shape of AX₃, with no lone pairs on A?
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Trigonal planar. The central atom and three bonded atoms lie in one plane.
12. kartīte
Jautājums
In an X–A–X bond angle, at which atom is the angle measured?
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At A, the central atom, between the two bonds to X atoms.
13. kartīte
Jautājums
Does a lone pair count as one VSEPR domain or two?
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One domain. The pair contains two electrons, but it occupies one region around the central atom.
14. kartīte
Jautājums
VSEPR molecular shape of AX₄, with no lone pairs on A?
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Tetrahedral. The four bonded atoms occupy the corners of a tetrahedron around A.
15. kartīte
Jautājums
VSEPR molecular shape of AX₂E?
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Bent, also called angular or V-shaped. There are two bonded atoms and one lone pair around A.
16. kartīte
Jautājums
What is the ideal X–A–X bond angle in AX₂ with no lone pairs?
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180°.
17. kartīte
Jautājums
What electron geometry does VSEPR assign to three domains around a central atom?
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Trigonal planar.
18. kartīte
Jautājums
VSEPR molecular shape of AX₃E?
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Trigonal pyramidal. Three bonded atoms and one lone pair occupy four electron domains.
19. kartīte
Jautājums
What is the ideal X–A–X bond angle in tetrahedral AX₄?
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About 109.5°.
20. kartīte
Jautājums
A central atom has two bonded neighbors and two lone pairs. What is its AXE notation?
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AX₂E₂.
21. kartīte
Jautājums
What is the ideal X–A–X bond angle in trigonal planar AX₃?
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120°.
22. kartīte
Jautājums
VSEPR molecular shape of AX₂E₂?
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Bent, also called angular or V-shaped. Two lone pairs occupy the other two domains.
23. kartīte
Jautājums
What is the electron geometry around A in AX₃E?
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Tetrahedral: three bonding domains plus one lone-pair domain.
24. kartīte
Jautājums
In O=C=O, how many electron domains surround carbon?
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Two domains. Each C=O double bond counts once.
25. kartīte
Jautājums
What is the electron geometry around A in AX₂E?
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Trigonal planar: two bonding domains plus one lone-pair domain.
26. kartīte
Jautājums
What molecular shape does VSEPR predict around carbon in CH₄?
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Tetrahedral. Carbon has four bonded neighbors and no lone pairs.
27. kartīte
Jautājums
A learner counts a double bond as two VSEPR domains. What should they correct?
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Count it as one domain. Bond order changes the number of shared electrons, not the number of bonded directions.
28. kartīte
Jautājums
What molecular shape does VSEPR predict around nitrogen in NH₃?
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Trigonal pyramidal. Nitrogen has three bonded neighbors and one lone pair.
29. kartīte
Jautājums
What electron geometry does VSEPR assign to four domains around a central atom?
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Tetrahedral.
30. kartīte
Jautājums
What molecular shape does VSEPR predict around oxygen in H₂O?
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Bent. Oxygen has two bonded neighbors and two lone pairs.
31. kartīte
Jautājums
What molecular shape does VSEPR predict around carbon in the carbonate ion, CO₃²⁻?
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Trigonal planar. The three C–O bonding directions give three domains, even when a Lewis structure shows one double bond.
32. kartīte
Jautājums
In the simple VSEPR model, how does a central lone pair usually affect neighboring bond angles?
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It tends to compress nearby bond angles because its electron density occupies more space near the central atom. This is a qualitative tendency, not a fixed number of degrees.
33. kartīte
Jautājums
A VSEPR center is trigonal pyramidal with four total domains. What is its AXE notation?
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AX₃E: three bonded atoms and one lone pair.
34. kartīte
Jautājums
Which two common AXE cases give a bent molecular shape with three or four total domains?
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AX₂E with three domains, and AX₂E₂ with four domains. Their electron geometries differ.
35. kartīte
Jautājums
What electron geometry does VSEPR assign to five domains around a central atom?
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Trigonal bipyramidal.
36. kartīte
Jautājums
What electron geometry does VSEPR assign to six domains around a central atom?
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Octahedral.
37. kartīte
Jautājums
Does an ideal VSEPR angle give the exact measured angle in every molecule of that shape?
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No. It is a geometric benchmark; lone pairs and the bonding environment can change actual angles.
38. kartīte
Jautājums
How many axial and equatorial positions are in a trigonal bipyramid?
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Two axial positions and three equatorial positions.
39. kartīte
Jautājums
VSEPR molecular shape of AX₅, with no lone pairs on A?
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Trigonal bipyramidal.
40. kartīte
Jautājums
VSEPR molecular shape of AX₆, with no lone pairs on A?
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Octahedral.
41. kartīte
Jautājums
VSEPR molecular shape of AX₄E in the usual lowest-repulsion arrangement?
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Seesaw. The lone pair occupies an equatorial position in a trigonal-bipyramidal domain arrangement.
42. kartīte
Jautājums
In an ideal trigonal bipyramid, what is the angle between two equatorial bonds?
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120°.
43. kartīte
Jautājums
VSEPR molecular shape of AX₃E₂ in the usual lowest-repulsion arrangement?
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T-shaped. Both lone pairs occupy equatorial positions.
44. kartīte
Jautājums
VSEPR molecular shape of AX₅E?
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Square pyramidal. One lone pair occupies the sixth position of an octahedral domain arrangement.
45. kartīte
Jautājums
In an ideal trigonal bipyramid, what is the angle between an axial bond and an equatorial bond?
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90°.
46. kartīte
Jautājums
VSEPR molecular shape of AX₂E₃ in the usual lowest-repulsion arrangement?
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Linear. Three equatorial lone pairs leave the two bonded atoms in opposite axial positions.
47. kartīte
Jautājums
VSEPR molecular shape of AX₄E₂ in the usual lowest-repulsion arrangement?
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Square planar. Two opposite lone pairs leave four bonded atoms in a square around A.
48. kartīte
Jautājums
In a trigonal-bipyramidal domain arrangement, which sites do lone pairs preferentially occupy?
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Equatorial sites, in the usual VSEPR arrangements with one to three lone pairs.
49. kartīte
Jautājums
Which X–A–X angles occur in an ideal octahedral AX₆ molecule?
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90° between adjacent bonds and 180° between opposite bonds.
50. kartīte
Jautājums
A VSEPR center has a seesaw shape and five total domains. What is its AXE notation?
Atbilde
AX₄E.
51. kartīte
Jautājums
A VSEPR center has a T-shaped molecular geometry and five total domains. What is its AXE notation?
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AX₃E₂.
52. kartīte
Jautājums
In an ideal trigonal bipyramid, what is the angle between its two axial bonds?
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180°. The axial positions lie on opposite sides of the central atom.
53. kartīte
Jautājums
A VSEPR center is square pyramidal with six total domains. What is its AXE notation?
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AX₅E.
54. kartīte
Jautājums
In the usual octahedral AX₄E₂ arrangement, how are the two lone pairs positioned relative to each other?
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Opposite each other, 180° apart in the ideal domain arrangement.
55. kartīte
Jautājums
What molecular shape does VSEPR predict for an isolated SF₄ molecule?
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Seesaw. Sulfur has four bonded fluorine atoms and one lone pair.
56. kartīte
Jautājums
What molecular shape does VSEPR predict for an isolated XeF₂ molecule?
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Linear. Xenon has two bonded fluorine atoms and three lone pairs.
57. kartīte
Jautājums
What is the electron geometry around A in AX₃E₂?
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Trigonal bipyramidal: three bonding domains plus two lone-pair domains.
58. kartīte
Jautājums
What molecular shape does VSEPR predict for an isolated BrF₅ molecule?
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Square pyramidal. Bromine has five bonded fluorine atoms and one lone pair.
59. kartīte
Jautājums
What molecular shape does VSEPR predict for an isolated XeF₄ molecule?
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Square planar. Xenon has four bonded fluorine atoms and two opposite lone pairs.
60. kartīte
Jautājums
What is the electron geometry around A in AX₄E?
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Trigonal bipyramidal: four bonding domains plus one lone-pair domain.
61. kartīte
Jautājums
What molecular shape does VSEPR predict for an isolated ClF₃ molecule?
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T-shaped. Chlorine has three bonded fluorine atoms and two equatorial lone pairs.
62. kartīte
Jautājums
What is the electron geometry around A in AX₅E?
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Octahedral: five bonding domains plus one lone-pair domain.
63. kartīte
Jautājums
What is the electron geometry around A in AX₂E₃?
Atbilde
Trigonal bipyramidal: two bonding domains plus three lone-pair domains.
64. kartīte
Jautājums
What molecular shape does VSEPR predict for an isolated SF₆ molecule?
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Octahedral. Sulfur has six bonded fluorine atoms and no lone pairs.
65. kartīte
Jautājums
Which bond angles occur in an idealized T-shaped AX₃E₂ arrangement?
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90° and 180°. These are parent-geometry benchmarks; a real molecule can be distorted.
66. kartīte
Jautājums
What is the electron geometry around A in AX₄E₂?
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Octahedral: four bonding domains plus two lone-pair domains.
67. kartīte
Jautājums
Why does an octahedral VSEPR arrangement have six domains despite the name’s reference to eight?
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The six domains point toward the six vertices of an octahedron. Eight refers to the solid’s faces.
68. kartīte
Jautājums
Why does a lone pair in AX₄E favor an equatorial site over an axial site?
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An equatorial site has two 90° interactions with other domains; an axial site has three. The equatorial choice reduces these close repulsions.
69. kartīte
Jautājums
Which common AXE cases give a linear molecular shape with two or five total domains?
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AX₂ with two domains, and AX₂E₃ with five domains. A linear shape alone does not determine the electron geometry.
70. kartīte
Jautājums
Which bond angles occur in an idealized square-pyramidal AX₅E arrangement?
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90° and 180°. Actual angles can deviate from these octahedral parent benchmarks.
71. kartīte
Jautājums
A VSEPR center is square planar with six total domains. What is its AXE notation?
Atbilde
AX₄E₂.
72. kartīte
Jautājums
A learner assigns every bent molecule the same bond angle. What information are they missing?
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The electron-domain arrangement and the particular molecule. Bent includes AX₂E and AX₂E₂, and actual angles depend on the species.
73. kartīte
Jautājums
A learner calls NH₃ tetrahedral because nitrogen has four domains. What shape distinction resolves the error?
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Tetrahedral is its electron geometry. Its molecular geometry is trigonal pyramidal because only the three bonded atoms define that shape.
74. kartīte
Jautājums
Why can four bonded atoms give tetrahedral AX₄ but square planar AX₄E₂?
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AX₄ has four total domains. AX₄E₂ has six total domains, with two opposite lone pairs in an octahedral arrangement.
75. kartīte
Jautājums
Which ideal parent angles are the benchmarks for an AX₄E seesaw arrangement?
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90°, 120°, and 180° from trigonal-bipyramidal electron geometry. Lone-pair repulsion can distort the actual bond angles.
76. kartīte
Jautājums
What molecular shape does VSEPR predict for an isolated PF₅ molecule?
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Trigonal bipyramidal. Phosphorus has five bonded fluorine atoms and no lone pairs.
77. kartīte
Jautājums
What is the electron geometry around A in AX₂E₂?
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Tetrahedral: two bonding domains plus two lone-pair domains.
78. kartīte
Jautājums
Which X–A–X bond angles occur in an ideal square-planar AX₄E₂ arrangement?
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90° between adjacent bonds and 180° between opposite bonds.
78 kartītes
VSEPR Flashcards: Molecular Geometry & Bond Angles
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