VSEPR Flashcards: Molecular Geometry & Bond Angles
Practice VSEPR shapes, electron geometry, lone pairs, AXE notation, and ideal bond angles with 78 focused English flashcards.
Über dieses Lernkartenset
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.
Karten in diesem Lernkartenset
Karte 1
Frage
In VSEPR, what is an electron domain around a central atom?
Antwort
A region of electron density: one bond to a neighboring atom, regardless of bond order, or one lone pair.
Karte 2
Frage
What does the VSEPR model use to predict a central atom’s geometry?
Antwort
Repulsion between electron domains. The domains favor an arrangement that reduces their mutual repulsion.
Karte 3
Frage
In AXₙEₘ notation, what does A represent?
Antwort
The central atom whose local geometry is being described.
Karte 4
Frage
How do electron geometry and molecular geometry differ in VSEPR?
Antwort
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.
Karte 5
Frage
How many VSEPR domains does one triple bond contribute at either bonded atom?
Antwort
One domain. Three shared electron pairs occupy one bonding direction.
Karte 6
Frage
In AXₙEₘ notation, what does n count?
Antwort
Atoms directly bonded to the central atom. A double or triple bond still contributes one X.
Karte 7
Frage
For a molecule with several central atoms, where do you apply VSEPR?
Antwort
At each central atom separately, using its own bonded neighbors and lone pairs.
Karte 8
Frage
In AXₙEₘ notation, what does m count?
Antwort
Lone pairs on the central atom. E counts pairs, not individual electrons.
Karte 9
Frage
For an AXₙEₘ center in the usual closed-shell VSEPR model, how many electron domains are present?
Antwort
n + m domains: bonded neighbors plus lone pairs.
Karte 10
Frage
VSEPR molecular shape of AX₂, with no lone pairs on A?
Antwort
Linear. The two bonded atoms lie on opposite sides of the central atom.
Karte 11
Frage
VSEPR molecular shape of AX₃, with no lone pairs on A?
Antwort
Trigonal planar. The central atom and three bonded atoms lie in one plane.
Karte 12
Frage
In an X–A–X bond angle, at which atom is the angle measured?
Antwort
At A, the central atom, between the two bonds to X atoms.
Karte 13
Frage
Does a lone pair count as one VSEPR domain or two?
Antwort
One domain. The pair contains two electrons, but it occupies one region around the central atom.
Karte 14
Frage
VSEPR molecular shape of AX₄, with no lone pairs on A?
Antwort
Tetrahedral. The four bonded atoms occupy the corners of a tetrahedron around A.
Karte 15
Frage
VSEPR molecular shape of AX₂E?
Antwort
Bent, also called angular or V-shaped. There are two bonded atoms and one lone pair around A.
Karte 16
Frage
What is the ideal X–A–X bond angle in AX₂ with no lone pairs?
Antwort
180°.
Karte 17
Frage
What electron geometry does VSEPR assign to three domains around a central atom?
Antwort
Trigonal planar.
Karte 18
Frage
VSEPR molecular shape of AX₃E?
Antwort
Trigonal pyramidal. Three bonded atoms and one lone pair occupy four electron domains.
Karte 19
Frage
What is the ideal X–A–X bond angle in tetrahedral AX₄?
Antwort
About 109.5°.
Karte 20
Frage
A central atom has two bonded neighbors and two lone pairs. What is its AXE notation?
Antwort
AX₂E₂.
Karte 21
Frage
What is the ideal X–A–X bond angle in trigonal planar AX₃?
Antwort
120°.
Karte 22
Frage
VSEPR molecular shape of AX₂E₂?
Antwort
Bent, also called angular or V-shaped. Two lone pairs occupy the other two domains.
Karte 23
Frage
What is the electron geometry around A in AX₃E?
Antwort
Tetrahedral: three bonding domains plus one lone-pair domain.
Karte 24
Frage
In O=C=O, how many electron domains surround carbon?
Antwort
Two domains. Each C=O double bond counts once.
Karte 25
Frage
What is the electron geometry around A in AX₂E?
Antwort
Trigonal planar: two bonding domains plus one lone-pair domain.
Karte 26
Frage
What molecular shape does VSEPR predict around carbon in CH₄?
Antwort
Tetrahedral. Carbon has four bonded neighbors and no lone pairs.
Karte 27
Frage
A learner counts a double bond as two VSEPR domains. What should they correct?
Antwort
Count it as one domain. Bond order changes the number of shared electrons, not the number of bonded directions.
Karte 28
Frage
What molecular shape does VSEPR predict around nitrogen in NH₃?
Antwort
Trigonal pyramidal. Nitrogen has three bonded neighbors and one lone pair.
Karte 29
Frage
What electron geometry does VSEPR assign to four domains around a central atom?
Antwort
Tetrahedral.
Karte 30
Frage
What molecular shape does VSEPR predict around oxygen in H₂O?
Antwort
Bent. Oxygen has two bonded neighbors and two lone pairs.
Karte 31
Frage
What molecular shape does VSEPR predict around carbon in the carbonate ion, CO₃²⁻?
Antwort
Trigonal planar. The three C–O bonding directions give three domains, even when a Lewis structure shows one double bond.
Karte 32
Frage
In the simple VSEPR model, how does a central lone pair usually affect neighboring bond angles?
Antwort
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.
Karte 33
Frage
A VSEPR center is trigonal pyramidal with four total domains. What is its AXE notation?
Antwort
AX₃E: three bonded atoms and one lone pair.
Karte 34
Frage
Which two common AXE cases give a bent molecular shape with three or four total domains?
Antwort
AX₂E with three domains, and AX₂E₂ with four domains. Their electron geometries differ.
Karte 35
Frage
What electron geometry does VSEPR assign to five domains around a central atom?
Antwort
Trigonal bipyramidal.
Karte 36
Frage
What electron geometry does VSEPR assign to six domains around a central atom?
Antwort
Octahedral.
Karte 37
Frage
Does an ideal VSEPR angle give the exact measured angle in every molecule of that shape?
Antwort
No. It is a geometric benchmark; lone pairs and the bonding environment can change actual angles.
Karte 38
Frage
How many axial and equatorial positions are in a trigonal bipyramid?
Antwort
Two axial positions and three equatorial positions.
Karte 39
Frage
VSEPR molecular shape of AX₅, with no lone pairs on A?
Antwort
Trigonal bipyramidal.
Karte 40
Frage
VSEPR molecular shape of AX₆, with no lone pairs on A?
Antwort
Octahedral.
Karte 41
Frage
VSEPR molecular shape of AX₄E in the usual lowest-repulsion arrangement?
Antwort
Seesaw. The lone pair occupies an equatorial position in a trigonal-bipyramidal domain arrangement.
Karte 42
Frage
In an ideal trigonal bipyramid, what is the angle between two equatorial bonds?
Antwort
120°.
Karte 43
Frage
VSEPR molecular shape of AX₃E₂ in the usual lowest-repulsion arrangement?
Antwort
T-shaped. Both lone pairs occupy equatorial positions.
Karte 44
Frage
VSEPR molecular shape of AX₅E?
Antwort
Square pyramidal. One lone pair occupies the sixth position of an octahedral domain arrangement.
Karte 45
Frage
In an ideal trigonal bipyramid, what is the angle between an axial bond and an equatorial bond?
Antwort
90°.
Karte 46
Frage
VSEPR molecular shape of AX₂E₃ in the usual lowest-repulsion arrangement?
Antwort
Linear. Three equatorial lone pairs leave the two bonded atoms in opposite axial positions.
Karte 47
Frage
VSEPR molecular shape of AX₄E₂ in the usual lowest-repulsion arrangement?
Antwort
Square planar. Two opposite lone pairs leave four bonded atoms in a square around A.
Karte 48
Frage
In a trigonal-bipyramidal domain arrangement, which sites do lone pairs preferentially occupy?
Antwort
Equatorial sites, in the usual VSEPR arrangements with one to three lone pairs.
Karte 49
Frage
Which X–A–X angles occur in an ideal octahedral AX₆ molecule?
Antwort
90° between adjacent bonds and 180° between opposite bonds.
Karte 50
Frage
A VSEPR center has a seesaw shape and five total domains. What is its AXE notation?
Antwort
AX₄E.
Karte 51
Frage
A VSEPR center has a T-shaped molecular geometry and five total domains. What is its AXE notation?
Antwort
AX₃E₂.
Karte 52
Frage
In an ideal trigonal bipyramid, what is the angle between its two axial bonds?
Antwort
180°. The axial positions lie on opposite sides of the central atom.
Karte 53
Frage
A VSEPR center is square pyramidal with six total domains. What is its AXE notation?
Antwort
AX₅E.
Karte 54
Frage
In the usual octahedral AX₄E₂ arrangement, how are the two lone pairs positioned relative to each other?
Antwort
Opposite each other, 180° apart in the ideal domain arrangement.
Karte 55
Frage
What molecular shape does VSEPR predict for an isolated SF₄ molecule?
Antwort
Seesaw. Sulfur has four bonded fluorine atoms and one lone pair.
Karte 56
Frage
What molecular shape does VSEPR predict for an isolated XeF₂ molecule?
Antwort
Linear. Xenon has two bonded fluorine atoms and three lone pairs.
Karte 57
Frage
What is the electron geometry around A in AX₃E₂?
Antwort
Trigonal bipyramidal: three bonding domains plus two lone-pair domains.
Karte 58
Frage
What molecular shape does VSEPR predict for an isolated BrF₅ molecule?
Antwort
Square pyramidal. Bromine has five bonded fluorine atoms and one lone pair.
Karte 59
Frage
What molecular shape does VSEPR predict for an isolated XeF₄ molecule?
Antwort
Square planar. Xenon has four bonded fluorine atoms and two opposite lone pairs.
Karte 60
Frage
What is the electron geometry around A in AX₄E?
Antwort
Trigonal bipyramidal: four bonding domains plus one lone-pair domain.
Karte 61
Frage
What molecular shape does VSEPR predict for an isolated ClF₃ molecule?
Antwort
T-shaped. Chlorine has three bonded fluorine atoms and two equatorial lone pairs.
Karte 62
Frage
What is the electron geometry around A in AX₅E?
Antwort
Octahedral: five bonding domains plus one lone-pair domain.
Karte 63
Frage
What is the electron geometry around A in AX₂E₃?
Antwort
Trigonal bipyramidal: two bonding domains plus three lone-pair domains.
Karte 64
Frage
What molecular shape does VSEPR predict for an isolated SF₆ molecule?
Antwort
Octahedral. Sulfur has six bonded fluorine atoms and no lone pairs.
Karte 65
Frage
Which bond angles occur in an idealized T-shaped AX₃E₂ arrangement?
Antwort
90° and 180°. These are parent-geometry benchmarks; a real molecule can be distorted.
Karte 66
Frage
What is the electron geometry around A in AX₄E₂?
Antwort
Octahedral: four bonding domains plus two lone-pair domains.
Karte 67
Frage
Why does an octahedral VSEPR arrangement have six domains despite the name’s reference to eight?
Antwort
The six domains point toward the six vertices of an octahedron. Eight refers to the solid’s faces.
Karte 68
Frage
Why does a lone pair in AX₄E favor an equatorial site over an axial site?
Antwort
An equatorial site has two 90° interactions with other domains; an axial site has three. The equatorial choice reduces these close repulsions.
Karte 69
Frage
Which common AXE cases give a linear molecular shape with two or five total domains?
Antwort
AX₂ with two domains, and AX₂E₃ with five domains. A linear shape alone does not determine the electron geometry.
Karte 70
Frage
Which bond angles occur in an idealized square-pyramidal AX₅E arrangement?
Antwort
90° and 180°. Actual angles can deviate from these octahedral parent benchmarks.
Karte 71
Frage
A VSEPR center is square planar with six total domains. What is its AXE notation?
Antwort
AX₄E₂.
Karte 72
Frage
A learner assigns every bent molecule the same bond angle. What information are they missing?
Antwort
The electron-domain arrangement and the particular molecule. Bent includes AX₂E and AX₂E₂, and actual angles depend on the species.
Karte 73
Frage
A learner calls NH₃ tetrahedral because nitrogen has four domains. What shape distinction resolves the error?
Antwort
Tetrahedral is its electron geometry. Its molecular geometry is trigonal pyramidal because only the three bonded atoms define that shape.
Karte 74
Frage
Why can four bonded atoms give tetrahedral AX₄ but square planar AX₄E₂?
Antwort
AX₄ has four total domains. AX₄E₂ has six total domains, with two opposite lone pairs in an octahedral arrangement.
Karte 75
Frage
Which ideal parent angles are the benchmarks for an AX₄E seesaw arrangement?
Antwort
90°, 120°, and 180° from trigonal-bipyramidal electron geometry. Lone-pair repulsion can distort the actual bond angles.
Karte 76
Frage
What molecular shape does VSEPR predict for an isolated PF₅ molecule?
Antwort
Trigonal bipyramidal. Phosphorus has five bonded fluorine atoms and no lone pairs.
Karte 77
Frage
What is the electron geometry around A in AX₂E₂?
Antwort
Tetrahedral: two bonding domains plus two lone-pair domains.
Karte 78
Frage
Which X–A–X bond angles occur in an ideal square-planar AX₄E₂ arrangement?
Antwort
90° between adjacent bonds and 180° between opposite bonds.
78 Karten
VSEPR Flashcards: Molecular Geometry & Bond Angles
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