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