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