VSEPR Flashcards: Molecular Geometry & Bond Angles
Practice VSEPR shapes, electron geometry, lone pairs, AXE notation, and ideal bond angles with 78 focused English flashcards.
Om denne bunke
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.
Kort i denne bunke
Kort 1
Spørgsmål
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.
Kort 2
Spørgsmål
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.
Kort 3
Spørgsmål
In AXₙEₘ notation, what does A represent?
Svar
The central atom whose local geometry is being described.
Kort 4
Spørgsmål
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.
Kort 5
Spørgsmål
How many VSEPR domains does one triple bond contribute at either bonded atom?
Svar
One domain. Three shared electron pairs occupy one bonding direction.
Kort 6
Spørgsmål
In AXₙEₘ notation, what does n count?
Svar
Atoms directly bonded to the central atom. A double or triple bond still contributes one X.
Kort 7
Spørgsmål
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.
Kort 8
Spørgsmål
In AXₙEₘ notation, what does m count?
Svar
Lone pairs on the central atom. E counts pairs, not individual electrons.
Kort 9
Spørgsmål
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.
Kort 10
Spørgsmål
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.
Kort 11
Spørgsmål
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.
Kort 12
Spørgsmål
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.
Kort 13
Spørgsmål
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.
Kort 14
Spørgsmål
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.
Kort 15
Spørgsmål
VSEPR molecular shape of AX₂E?
Svar
Bent, also called angular or V-shaped. There are two bonded atoms and one lone pair around A.
Kort 16
Spørgsmål
What is the ideal X–A–X bond angle in AX₂ with no lone pairs?
Svar
180°.
Kort 17
Spørgsmål
What electron geometry does VSEPR assign to three domains around a central atom?
Svar
Trigonal planar.
Kort 18
Spørgsmål
VSEPR molecular shape of AX₃E?
Svar
Trigonal pyramidal. Three bonded atoms and one lone pair occupy four electron domains.
Kort 19
Spørgsmål
What is the ideal X–A–X bond angle in tetrahedral AX₄?
Svar
About 109.5°.
Kort 20
Spørgsmål
A central atom has two bonded neighbors and two lone pairs. What is its AXE notation?
Svar
AX₂E₂.
Kort 21
Spørgsmål
What is the ideal X–A–X bond angle in trigonal planar AX₃?
Svar
120°.
Kort 22
Spørgsmål
VSEPR molecular shape of AX₂E₂?
Svar
Bent, also called angular or V-shaped. Two lone pairs occupy the other two domains.
Kort 23
Spørgsmål
What is the electron geometry around A in AX₃E?
Svar
Tetrahedral: three bonding domains plus one lone-pair domain.
Kort 24
Spørgsmål
In O=C=O, how many electron domains surround carbon?
Svar
Two domains. Each C=O double bond counts once.
Kort 25
Spørgsmål
What is the electron geometry around A in AX₂E?
Svar
Trigonal planar: two bonding domains plus one lone-pair domain.
Kort 26
Spørgsmål
What molecular shape does VSEPR predict around carbon in CH₄?
Svar
Tetrahedral. Carbon has four bonded neighbors and no lone pairs.
Kort 27
Spørgsmål
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.
Kort 28
Spørgsmål
What molecular shape does VSEPR predict around nitrogen in NH₃?
Svar
Trigonal pyramidal. Nitrogen has three bonded neighbors and one lone pair.
Kort 29
Spørgsmål
What electron geometry does VSEPR assign to four domains around a central atom?
Svar
Tetrahedral.
Kort 30
Spørgsmål
What molecular shape does VSEPR predict around oxygen in H₂O?
Svar
Bent. Oxygen has two bonded neighbors and two lone pairs.
Kort 31
Spørgsmål
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.
Kort 32
Spørgsmål
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.
Kort 33
Spørgsmål
A VSEPR center is trigonal pyramidal with four total domains. What is its AXE notation?
Svar
AX₃E: three bonded atoms and one lone pair.
Kort 34
Spørgsmål
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.
Kort 35
Spørgsmål
What electron geometry does VSEPR assign to five domains around a central atom?
Svar
Trigonal bipyramidal.
Kort 36
Spørgsmål
What electron geometry does VSEPR assign to six domains around a central atom?
Svar
Octahedral.
Kort 37
Spørgsmål
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.
Kort 38
Spørgsmål
How many axial and equatorial positions are in a trigonal bipyramid?
Svar
Two axial positions and three equatorial positions.
Kort 39
Spørgsmål
VSEPR molecular shape of AX₅, with no lone pairs on A?
Svar
Trigonal bipyramidal.
Kort 40
Spørgsmål
VSEPR molecular shape of AX₆, with no lone pairs on A?
Svar
Octahedral.
Kort 41
Spørgsmål
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.
Kort 42
Spørgsmål
In an ideal trigonal bipyramid, what is the angle between two equatorial bonds?
Svar
120°.
Kort 43
Spørgsmål
VSEPR molecular shape of AX₃E₂ in the usual lowest-repulsion arrangement?
Svar
T-shaped. Both lone pairs occupy equatorial positions.
Kort 44
Spørgsmål
VSEPR molecular shape of AX₅E?
Svar
Square pyramidal. One lone pair occupies the sixth position of an octahedral domain arrangement.
Kort 45
Spørgsmål
In an ideal trigonal bipyramid, what is the angle between an axial bond and an equatorial bond?
Svar
90°.
Kort 46
Spørgsmål
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.
Kort 47
Spørgsmål
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.
Kort 48
Spørgsmål
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.
Kort 49
Spørgsmål
Which X–A–X angles occur in an ideal octahedral AX₆ molecule?
Svar
90° between adjacent bonds and 180° between opposite bonds.
Kort 50
Spørgsmål
A VSEPR center has a seesaw shape and five total domains. What is its AXE notation?
Svar
AX₄E.
Kort 51
Spørgsmål
A VSEPR center has a T-shaped molecular geometry and five total domains. What is its AXE notation?
Svar
AX₃E₂.
Kort 52
Spørgsmål
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.
Kort 53
Spørgsmål
A VSEPR center is square pyramidal with six total domains. What is its AXE notation?
Svar
AX₅E.
Kort 54
Spørgsmål
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.
Kort 55
Spørgsmål
What molecular shape does VSEPR predict for an isolated SF₄ molecule?
Svar
Seesaw. Sulfur has four bonded fluorine atoms and one lone pair.
Kort 56
Spørgsmål
What molecular shape does VSEPR predict for an isolated XeF₂ molecule?
Svar
Linear. Xenon has two bonded fluorine atoms and three lone pairs.
Kort 57
Spørgsmål
What is the electron geometry around A in AX₃E₂?
Svar
Trigonal bipyramidal: three bonding domains plus two lone-pair domains.
Kort 58
Spørgsmål
What molecular shape does VSEPR predict for an isolated BrF₅ molecule?
Svar
Square pyramidal. Bromine has five bonded fluorine atoms and one lone pair.
Kort 59
Spørgsmål
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.
Kort 60
Spørgsmål
What is the electron geometry around A in AX₄E?
Svar
Trigonal bipyramidal: four bonding domains plus one lone-pair domain.
Kort 61
Spørgsmål
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.
Kort 62
Spørgsmål
What is the electron geometry around A in AX₅E?
Svar
Octahedral: five bonding domains plus one lone-pair domain.
Kort 63
Spørgsmål
What is the electron geometry around A in AX₂E₃?
Svar
Trigonal bipyramidal: two bonding domains plus three lone-pair domains.
Kort 64
Spørgsmål
What molecular shape does VSEPR predict for an isolated SF₆ molecule?
Svar
Octahedral. Sulfur has six bonded fluorine atoms and no lone pairs.
Kort 65
Spørgsmål
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.
Kort 66
Spørgsmål
What is the electron geometry around A in AX₄E₂?
Svar
Octahedral: four bonding domains plus two lone-pair domains.
Kort 67
Spørgsmål
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.
Kort 68
Spørgsmål
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.
Kort 69
Spørgsmål
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.
Kort 70
Spørgsmål
Which bond angles occur in an idealized square-pyramidal AX₅E arrangement?
Svar
90° and 180°. Actual angles can deviate from these octahedral parent benchmarks.
Kort 71
Spørgsmål
A VSEPR center is square planar with six total domains. What is its AXE notation?
Svar
AX₄E₂.
Kort 72
Spørgsmål
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.
Kort 73
Spørgsmål
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.
Kort 74
Spørgsmål
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.
Kort 75
Spørgsmål
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.
Kort 76
Spørgsmål
What molecular shape does VSEPR predict for an isolated PF₅ molecule?
Svar
Trigonal bipyramidal. Phosphorus has five bonded fluorine atoms and no lone pairs.
Kort 77
Spørgsmål
What is the electron geometry around A in AX₂E₂?
Svar
Tetrahedral: two bonding domains plus two lone-pair domains.
Kort 78
Spørgsmål
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 kort
VSEPR Flashcards: Molecular Geometry & Bond Angles
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