Question 1

According to VSEPR theory, what is the electron domain geometry and predicted bond angle for a molecule with three electron groups around the central atom?

Accepted Answer

Trigonal planar, $$120^	ext{o}$$

Question 2

Which of the following molecules is expected to have a bent molecular geometry due to the presence of lone pairs on the central atom?

Accepted Answer

H$$_2O$$

Question 3

In VSEPR theory, how are double and triple bonds counted when determining the number of electron groups around a central atom?

Accepted Answer

Each double or triple bond counts as a single electron group

Question 4

Which arrangement of electron domains minimizes repulsion for a molecule with five electron groups around the central atom?

Accepted Answer

Trigonal bipyramidal

Question 5

What is the effect of lone pairs on bond angles in a molecule such as NH$$_3$$ compared to the ideal tetrahedral angle?

Accepted Answer

Lone pairs decrease the bond angle due to increased repulsion

Question 6

For a molecule with six electron groups around the central atom, such as SF$$_6$$, what is the electron domain geometry and the bond angle?

Accepted Answer

Octahedral, $$90^	ext{o}$$

Question 7

Which of the following best describes the molecular geometry and bond angle of CH$$_4$$?

Accepted Answer

Tetrahedral, $$109.5^	ext{o}$$

Question 8

When drawing the 3D structure of a molecule using line-dash-wedge notation, what does a wedge represent?

Accepted Answer

A bond coming out of the page towards you

Question 9

Which of the following statements about molecular polarity is correct?

Accepted Answer

A molecule is nonpolar if the vector sum of all bond dipole moments is zero

Question 10

In a trigonal bipyramidal geometry, where should lone pairs be placed to minimize repulsion?

Accepted Answer

In the equatorial positions

Question 11

Which molecule is expected to be nonpolar due to its molecular geometry, even though it contains polar bonds?

Accepted Answer

CO$$_2$$

Question 12

What is the correct order of repulsion strength among electron groups?

Accepted Answer

Lone pair $$\u003e$$ triple bond $$\u003e$$ double bond $$\u003e$$ single bond

Question 13

A molecule has four electron groups: two bonding pairs and two lone pairs. What is its molecular geometry and approximate bond angle?

Accepted Answer

Bent, $$104.5^	ext{o}$$

Question 14

Which of the following is the correct strategy for predicting the 3D structure of a larger molecule using VSEPR theory?

Accepted Answer

Draw the Lewis structure, identify centers, determine electron pairs and lone pairs, assign geometry, and use line-dash-wedge notation

Question 15

Which of the following molecules has a trigonal planar electron domain geometry?

Accepted Answer

BF$$_3$$

Question 16

If a molecule has five electron groups and one of them is a lone pair, what is the resulting molecular geometry?

Accepted Answer

Seesaw

Question 17

Which of the following best explains why the bond angle in H$$_2O is $$less than the ideal tetrahedral angle?

Accepted Answer

The presence of two lone pairs increases repulsion, compressing the bond angle

Question 18

Which of the following molecules would have a molecular dipole moment pointing from the central atom towards the more electronegative atom?

Accepted Answer

HF

Question 19

In the context of VSEPR theory, what is the molecular geometry of PH$$_3$$?

Accepted Answer

Trigonal pyramidal

Question 20

A molecule has six electron groups, two of which are lone pairs. According to VSEPR theory, what is its molecular geometry?

Accepted Answer

Square planar

Covalent Bonding II: Molecular Shapes, VSEPR Theory, and Advanced Bonding Models

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