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