VSEPR Theory and Molecular Shapes

Flashcards covering VSEPR theory, molecule shapes, bond angles, and the calculation of electron pairs and lone pairs.

VSEPR is a model used to predict the __________ of molecules.

shapes

According to VSEPR theory, electron pairs repel each other and adopt an arrangement that __________ repulsion.

minimises

The order of strengths of repulsion is: __________ > BONDED PAIR/ LONE PAIR > BONDED PAIR/BONDED PAIR.

LONE PAIR/LONE PAIR

Each lone pair reduces the bond angle by APPROXIMATELY __________ degrees.

$$2.5$$

A molecule with $2$ bonding pairs and $0$ lone pairs has a LINEAR shape and a bond angle of __________ degrees.

$$180$$

A molecule with $3$ bonding pairs and $0$ lone pairs has a TRIGONAL PLANAR shape and a bond angle of __________ degrees.

$$120$$

A BENt shape associated with $3$ electron pairs ($2$ bonding, $1$ lone) has a bond angle of approximately __________ degrees.

$$~119$$

A molecule with $4$ bonding pairs and $0$ lone pairs has a TETRAHEDRAL shape and a bond angle of __________ degrees.

$$109.5$$

A TRIGONAL PYRAMIDAL shape ($3$ bonding, $1$ lone) has a bond angle of approximately __________ degrees.

$$~107$$

A BENT shape associated with $4$ electron pairs ($2$ bonding, $2$ lone) has a bond angle of approximately __________ degrees.

$$~104.5$$

A TRIGONAL BIPYRAMIDAL shape has bond angles of __________ degrees.

$$90/120$$

A SAWHORSE shape ($4$ bonding, $1$ lone) has bond angles of __________ degrees.

$$<90/<120$$

A T-SHAPED molecule with $5$ electron pairs ($3$ bonding, $2$ lone) has a bond angle of __________ degrees.

$$90$$

An OCTAHEDRAL molecule ($6$ bonding pairs) has a bond angle of __________ degrees.

$$90$$

A SQUARE PYRAMIDAL shape ($5$ bonding, $1$ lone) has a bond angle of approximately __________ degrees.

$$~90$$

A SQUARE PLANAR shape ($4$ bonding, $2$ lone) has a bond angle of __________ degrees.

$$90$$

To find the number of electron pairs, divide the total valence count (adjusted for bonds and charges) by __________.

$$2$$

To find the number of lone pairs, subtract the number of atoms bonded to the central atom from the number of __________.

electron pairs

VSEPR theory fails for transition metal compounds and __________ species.

Isoelectronic