Question 1

According to VSEPR theory, what is the electron geometry and approximate bond angle of a molecule with three regions of electron density around the central atom, such as BF$$_3$$?

Accepted Answer

Trigonal planar, $$120^{\circ}$$

Question 2

Which of the following molecules is nonpolar despite having polar bonds?

Accepted Answer

CO$$_2$$

Question 3

What is the molecular shape and bond angle of CH$$_4$$ according to VSEPR theory?

Accepted Answer

Tetrahedral, $$109.5^{\circ}$$

Question 4

Which statement best explains why H$$_2O is a $$polar molecule?

Accepted Answer

It has polar O-H bonds and a bent molecular shape, resulting in a net dipole moment.

Question 5

A molecule has four regions of electron density: three bonding pairs and one lone pair. What is its molecular shape?

Accepted Answer

Trigonal pyramidal

Question 6

Which intermolecular force is present in all molecules, regardless of polarity?

Accepted Answer

London dispersion forces

Question 7

Why do London dispersion forces increase with increasing molar mass?

Accepted Answer

Larger molecules have more electrons, leading to greater temporary dipoles.

Question 8

Which of the following best describes the electron geometry and molecular shape of NH$$_3$$?

Accepted Answer

Electron geometry: tetrahedral; molecular shape: trigonal pyramidal

Question 9

Which molecule would you expect to have the highest boiling point due to intermolecular forces?

Accepted Answer

H$$_2O$$

Question 10

A molecule has two regions of electron density and no lone pairs on the central atom. What is its electron geometry and bond angle?

Accepted Answer

Linear, $$180^{\circ}$$

Question 11

Which of the following statements about polarity is correct?

Accepted Answer

A molecule can have polar bonds but still be nonpolar if the bond dipoles cancel.

Question 12

Which of the following molecules has a bent molecular shape?

Accepted Answer

H$$_2O$$

Question 13

In a tetrahedral molecule where all four substituents are the same, what is the overall molecular polarity?

Accepted Answer

Nonpolar, because all bond dipoles cancel out

Question 14

Which of the following best explains why CO$$_2 is a $$nonpolar molecule?

Accepted Answer

The molecule is linear and the bond dipoles are equal and opposite, canceling each other out.

Question 15

Which of the following molecules would exhibit dipole-dipole interactions as the dominant intermolecular force?

Accepted Answer

HCl

Question 16

A molecule has two bonds and two lone pairs on the central atom. What is its molecular shape and approximate bond angle?

Accepted Answer

Bent, $$104.5^{\circ}$$

Question 17

Which of the following is true about London dispersion forces?

Accepted Answer

They are present in all molecules but are only significant in nonpolar molecules.

Question 18

Which factor is most important in determining the shape of a molecule according to VSEPR theory?

Accepted Answer

The number of regions of electron density around the central atom

Question 19

Which of the following best describes the difference between electron geometry and molecular shape?

Accepted Answer

Electron geometry considers all regions of electron density, while molecular shape considers only the positions of atoms.

Question 20

Which of the following molecules has a trigonal planar electron geometry and a bent molecular shape?

Accepted Answer

SO$$_2$$

Molecular Shape, Polarity, and Intermolecular Forces in Organic Chemistry

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