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