VSEPR Flashcards: Molecular Geometry & Bond Angles
Practice VSEPR shapes, electron geometry, lone pairs, AXE notation, and ideal bond angles with 78 focused English flashcards.
Apie šį rinkinį
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.
Šio rinkinio kortelės
1 kortelė
Klausimas
In VSEPR, what is an electron domain around a central atom?
Atsakymas
A region of electron density: one bond to a neighboring atom, regardless of bond order, or one lone pair.
2 kortelė
Klausimas
What does the VSEPR model use to predict a central atom’s geometry?
Atsakymas
Repulsion between electron domains. The domains favor an arrangement that reduces their mutual repulsion.
3 kortelė
Klausimas
In AXₙEₘ notation, what does A represent?
Atsakymas
The central atom whose local geometry is being described.
4 kortelė
Klausimas
How do electron geometry and molecular geometry differ in VSEPR?
Atsakymas
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 kortelė
Klausimas
How many VSEPR domains does one triple bond contribute at either bonded atom?
Atsakymas
One domain. Three shared electron pairs occupy one bonding direction.
6 kortelė
Klausimas
In AXₙEₘ notation, what does n count?
Atsakymas
Atoms directly bonded to the central atom. A double or triple bond still contributes one X.
7 kortelė
Klausimas
For a molecule with several central atoms, where do you apply VSEPR?
Atsakymas
At each central atom separately, using its own bonded neighbors and lone pairs.
8 kortelė
Klausimas
In AXₙEₘ notation, what does m count?
Atsakymas
Lone pairs on the central atom. E counts pairs, not individual electrons.
9 kortelė
Klausimas
For an AXₙEₘ center in the usual closed-shell VSEPR model, how many electron domains are present?
Atsakymas
n + m domains: bonded neighbors plus lone pairs.
10 kortelė
Klausimas
VSEPR molecular shape of AX₂, with no lone pairs on A?
Atsakymas
Linear. The two bonded atoms lie on opposite sides of the central atom.
11 kortelė
Klausimas
VSEPR molecular shape of AX₃, with no lone pairs on A?
Atsakymas
Trigonal planar. The central atom and three bonded atoms lie in one plane.
12 kortelė
Klausimas
In an X–A–X bond angle, at which atom is the angle measured?
Atsakymas
At A, the central atom, between the two bonds to X atoms.
13 kortelė
Klausimas
Does a lone pair count as one VSEPR domain or two?
Atsakymas
One domain. The pair contains two electrons, but it occupies one region around the central atom.
14 kortelė
Klausimas
VSEPR molecular shape of AX₄, with no lone pairs on A?
Atsakymas
Tetrahedral. The four bonded atoms occupy the corners of a tetrahedron around A.
15 kortelė
Klausimas
VSEPR molecular shape of AX₂E?
Atsakymas
Bent, also called angular or V-shaped. There are two bonded atoms and one lone pair around A.
16 kortelė
Klausimas
What is the ideal X–A–X bond angle in AX₂ with no lone pairs?
Atsakymas
180°.
17 kortelė
Klausimas
What electron geometry does VSEPR assign to three domains around a central atom?
Atsakymas
Trigonal planar.
18 kortelė
Klausimas
VSEPR molecular shape of AX₃E?
Atsakymas
Trigonal pyramidal. Three bonded atoms and one lone pair occupy four electron domains.
19 kortelė
Klausimas
What is the ideal X–A–X bond angle in tetrahedral AX₄?
Atsakymas
About 109.5°.
20 kortelė
Klausimas
A central atom has two bonded neighbors and two lone pairs. What is its AXE notation?
Atsakymas
AX₂E₂.
21 kortelė
Klausimas
What is the ideal X–A–X bond angle in trigonal planar AX₃?
Atsakymas
120°.
22 kortelė
Klausimas
VSEPR molecular shape of AX₂E₂?
Atsakymas
Bent, also called angular or V-shaped. Two lone pairs occupy the other two domains.
23 kortelė
Klausimas
What is the electron geometry around A in AX₃E?
Atsakymas
Tetrahedral: three bonding domains plus one lone-pair domain.
24 kortelė
Klausimas
In O=C=O, how many electron domains surround carbon?
Atsakymas
Two domains. Each C=O double bond counts once.
25 kortelė
Klausimas
What is the electron geometry around A in AX₂E?
Atsakymas
Trigonal planar: two bonding domains plus one lone-pair domain.
26 kortelė
Klausimas
What molecular shape does VSEPR predict around carbon in CH₄?
Atsakymas
Tetrahedral. Carbon has four bonded neighbors and no lone pairs.
27 kortelė
Klausimas
A learner counts a double bond as two VSEPR domains. What should they correct?
Atsakymas
Count it as one domain. Bond order changes the number of shared electrons, not the number of bonded directions.
28 kortelė
Klausimas
What molecular shape does VSEPR predict around nitrogen in NH₃?
Atsakymas
Trigonal pyramidal. Nitrogen has three bonded neighbors and one lone pair.
29 kortelė
Klausimas
What electron geometry does VSEPR assign to four domains around a central atom?
Atsakymas
Tetrahedral.
30 kortelė
Klausimas
What molecular shape does VSEPR predict around oxygen in H₂O?
Atsakymas
Bent. Oxygen has two bonded neighbors and two lone pairs.
31 kortelė
Klausimas
What molecular shape does VSEPR predict around carbon in the carbonate ion, CO₃²⁻?
Atsakymas
Trigonal planar. The three C–O bonding directions give three domains, even when a Lewis structure shows one double bond.
32 kortelė
Klausimas
In the simple VSEPR model, how does a central lone pair usually affect neighboring bond angles?
Atsakymas
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 kortelė
Klausimas
A VSEPR center is trigonal pyramidal with four total domains. What is its AXE notation?
Atsakymas
AX₃E: three bonded atoms and one lone pair.
34 kortelė
Klausimas
Which two common AXE cases give a bent molecular shape with three or four total domains?
Atsakymas
AX₂E with three domains, and AX₂E₂ with four domains. Their electron geometries differ.
35 kortelė
Klausimas
What electron geometry does VSEPR assign to five domains around a central atom?
Atsakymas
Trigonal bipyramidal.
36 kortelė
Klausimas
What electron geometry does VSEPR assign to six domains around a central atom?
Atsakymas
Octahedral.
37 kortelė
Klausimas
Does an ideal VSEPR angle give the exact measured angle in every molecule of that shape?
Atsakymas
No. It is a geometric benchmark; lone pairs and the bonding environment can change actual angles.
38 kortelė
Klausimas
How many axial and equatorial positions are in a trigonal bipyramid?
Atsakymas
Two axial positions and three equatorial positions.
39 kortelė
Klausimas
VSEPR molecular shape of AX₅, with no lone pairs on A?
Atsakymas
Trigonal bipyramidal.
40 kortelė
Klausimas
VSEPR molecular shape of AX₆, with no lone pairs on A?
Atsakymas
Octahedral.
41 kortelė
Klausimas
VSEPR molecular shape of AX₄E in the usual lowest-repulsion arrangement?
Atsakymas
Seesaw. The lone pair occupies an equatorial position in a trigonal-bipyramidal domain arrangement.
42 kortelė
Klausimas
In an ideal trigonal bipyramid, what is the angle between two equatorial bonds?
Atsakymas
120°.
43 kortelė
Klausimas
VSEPR molecular shape of AX₃E₂ in the usual lowest-repulsion arrangement?
Atsakymas
T-shaped. Both lone pairs occupy equatorial positions.
44 kortelė
Klausimas
VSEPR molecular shape of AX₅E?
Atsakymas
Square pyramidal. One lone pair occupies the sixth position of an octahedral domain arrangement.
45 kortelė
Klausimas
In an ideal trigonal bipyramid, what is the angle between an axial bond and an equatorial bond?
Atsakymas
90°.
46 kortelė
Klausimas
VSEPR molecular shape of AX₂E₃ in the usual lowest-repulsion arrangement?
Atsakymas
Linear. Three equatorial lone pairs leave the two bonded atoms in opposite axial positions.
47 kortelė
Klausimas
VSEPR molecular shape of AX₄E₂ in the usual lowest-repulsion arrangement?
Atsakymas
Square planar. Two opposite lone pairs leave four bonded atoms in a square around A.
48 kortelė
Klausimas
In a trigonal-bipyramidal domain arrangement, which sites do lone pairs preferentially occupy?
Atsakymas
Equatorial sites, in the usual VSEPR arrangements with one to three lone pairs.
49 kortelė
Klausimas
Which X–A–X angles occur in an ideal octahedral AX₆ molecule?
Atsakymas
90° between adjacent bonds and 180° between opposite bonds.
50 kortelė
Klausimas
A VSEPR center has a seesaw shape and five total domains. What is its AXE notation?
Atsakymas
AX₄E.
51 kortelė
Klausimas
A VSEPR center has a T-shaped molecular geometry and five total domains. What is its AXE notation?
Atsakymas
AX₃E₂.
52 kortelė
Klausimas
In an ideal trigonal bipyramid, what is the angle between its two axial bonds?
Atsakymas
180°. The axial positions lie on opposite sides of the central atom.
53 kortelė
Klausimas
A VSEPR center is square pyramidal with six total domains. What is its AXE notation?
Atsakymas
AX₅E.
54 kortelė
Klausimas
In the usual octahedral AX₄E₂ arrangement, how are the two lone pairs positioned relative to each other?
Atsakymas
Opposite each other, 180° apart in the ideal domain arrangement.
55 kortelė
Klausimas
What molecular shape does VSEPR predict for an isolated SF₄ molecule?
Atsakymas
Seesaw. Sulfur has four bonded fluorine atoms and one lone pair.
56 kortelė
Klausimas
What molecular shape does VSEPR predict for an isolated XeF₂ molecule?
Atsakymas
Linear. Xenon has two bonded fluorine atoms and three lone pairs.
57 kortelė
Klausimas
What is the electron geometry around A in AX₃E₂?
Atsakymas
Trigonal bipyramidal: three bonding domains plus two lone-pair domains.
58 kortelė
Klausimas
What molecular shape does VSEPR predict for an isolated BrF₅ molecule?
Atsakymas
Square pyramidal. Bromine has five bonded fluorine atoms and one lone pair.
59 kortelė
Klausimas
What molecular shape does VSEPR predict for an isolated XeF₄ molecule?
Atsakymas
Square planar. Xenon has four bonded fluorine atoms and two opposite lone pairs.
60 kortelė
Klausimas
What is the electron geometry around A in AX₄E?
Atsakymas
Trigonal bipyramidal: four bonding domains plus one lone-pair domain.
61 kortelė
Klausimas
What molecular shape does VSEPR predict for an isolated ClF₃ molecule?
Atsakymas
T-shaped. Chlorine has three bonded fluorine atoms and two equatorial lone pairs.
62 kortelė
Klausimas
What is the electron geometry around A in AX₅E?
Atsakymas
Octahedral: five bonding domains plus one lone-pair domain.
63 kortelė
Klausimas
What is the electron geometry around A in AX₂E₃?
Atsakymas
Trigonal bipyramidal: two bonding domains plus three lone-pair domains.
64 kortelė
Klausimas
What molecular shape does VSEPR predict for an isolated SF₆ molecule?
Atsakymas
Octahedral. Sulfur has six bonded fluorine atoms and no lone pairs.
65 kortelė
Klausimas
Which bond angles occur in an idealized T-shaped AX₃E₂ arrangement?
Atsakymas
90° and 180°. These are parent-geometry benchmarks; a real molecule can be distorted.
66 kortelė
Klausimas
What is the electron geometry around A in AX₄E₂?
Atsakymas
Octahedral: four bonding domains plus two lone-pair domains.
67 kortelė
Klausimas
Why does an octahedral VSEPR arrangement have six domains despite the name’s reference to eight?
Atsakymas
The six domains point toward the six vertices of an octahedron. Eight refers to the solid’s faces.
68 kortelė
Klausimas
Why does a lone pair in AX₄E favor an equatorial site over an axial site?
Atsakymas
An equatorial site has two 90° interactions with other domains; an axial site has three. The equatorial choice reduces these close repulsions.
69 kortelė
Klausimas
Which common AXE cases give a linear molecular shape with two or five total domains?
Atsakymas
AX₂ with two domains, and AX₂E₃ with five domains. A linear shape alone does not determine the electron geometry.
70 kortelė
Klausimas
Which bond angles occur in an idealized square-pyramidal AX₅E arrangement?
Atsakymas
90° and 180°. Actual angles can deviate from these octahedral parent benchmarks.
71 kortelė
Klausimas
A VSEPR center is square planar with six total domains. What is its AXE notation?
Atsakymas
AX₄E₂.
72 kortelė
Klausimas
A learner assigns every bent molecule the same bond angle. What information are they missing?
Atsakymas
The electron-domain arrangement and the particular molecule. Bent includes AX₂E and AX₂E₂, and actual angles depend on the species.
73 kortelė
Klausimas
A learner calls NH₃ tetrahedral because nitrogen has four domains. What shape distinction resolves the error?
Atsakymas
Tetrahedral is its electron geometry. Its molecular geometry is trigonal pyramidal because only the three bonded atoms define that shape.
74 kortelė
Klausimas
Why can four bonded atoms give tetrahedral AX₄ but square planar AX₄E₂?
Atsakymas
AX₄ has four total domains. AX₄E₂ has six total domains, with two opposite lone pairs in an octahedral arrangement.
75 kortelė
Klausimas
Which ideal parent angles are the benchmarks for an AX₄E seesaw arrangement?
Atsakymas
90°, 120°, and 180° from trigonal-bipyramidal electron geometry. Lone-pair repulsion can distort the actual bond angles.
76 kortelė
Klausimas
What molecular shape does VSEPR predict for an isolated PF₅ molecule?
Atsakymas
Trigonal bipyramidal. Phosphorus has five bonded fluorine atoms and no lone pairs.
77 kortelė
Klausimas
What is the electron geometry around A in AX₂E₂?
Atsakymas
Tetrahedral: two bonding domains plus two lone-pair domains.
78 kortelė
Klausimas
Which X–A–X bond angles occur in an ideal square-planar AX₄E₂ arrangement?
Atsakymas
90° between adjacent bonds and 180° between opposite bonds.
78 kortelės
VSEPR Flashcards: Molecular Geometry & Bond Angles
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