Question 1

Which of the following statements best explains why artificial sweeteners can taste sweeter than sugar?

Accepted Answer

Artificial sweeteners fit into the T1r3 receptor more snugly and sometimes bind stronger than sugar, causing a more intense nerve signal.

Question 2

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

Accepted Answer

Trigonal planar geometry, $$120\degree$$

Question 3

A molecule has four electron groups around its central atom, two of which are lone pairs. What is its molecular geometry and approximate bond angle?

Accepted Answer

Bent geometry, $$104.5\degree$$

Question 4

Which of the following best describes the effect of lone pairs on bond angles in a molecule?

Accepted Answer

Lone pairs decrease bond angles because they exert greater repulsion than bonding pairs.

Question 5

What is the molecular geometry of $$\mathrm{$$BrF_3$$}$$ and why?

Accepted Answer

$$\mathrm{$$BrF_3$$}$$ has a trigonal bipyramidal electron geometry and a T-shaped molecular geometry due to two lone pairs occupying equatorial positions.

Question 6

Which molecule is expected to have a net dipole moment and be polar?

Accepted Answer

$$\mathrm{H_2O}$$

Question 7

A molecule has six electron groups around its central atom, with one lone pair. What is its molecular geometry and bond angle?

Accepted Answer

Square pyramidal geometry, bond angles less than $$90\degree$$

Question 8

Which of the following statements about sigma ($$\sigma) $$and pi ($$\pi) $$bonds is correct?

Accepted Answer

$$\sigma$$ bonds result from the overlap of orbitals along the axis between two nuclei and are stronger than $$\pi$$ bonds.

Question 9

What is the hybridization of the central atom in $$\mathrm{SF_6$}$$?

Accepted Answer

$$sp^3d^2$

Question 10

Which of the following molecules is predicted to be paramagnetic according to molecular orbital theory, but not by Lewis or valence bond theory?

Accepted Answer

$$\mathrm{O_2$}$$

Question 11

What is the bond order of $$\mathrm{O_2$}$$ according to molecular orbital theory?

Accepted Answer

$$2$$

Question 12

Which hybridization corresponds to a central atom with trigonal bipyramidal electron geometry?

Accepted Answer

$$sp^3d$

Question 13

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

Accepted Answer

Electron geometry considers all electron groups (bonds and lone pairs), while molecular geometry considers only the arrangement of atoms.

Question 14

Which of the following molecules will have a square planar molecular geometry?

Accepted Answer

$$\mathrm{$$XeF_4$$}$$

Question 15

Which step is NOT part of the process for predicting molecular geometry using VSEPR theory?

Accepted Answer

Use the periodic table to find the atomic mass.

Question 16

Why do lone pairs occupy equatorial positions in a trigonal bipyramidal geometry?

Accepted Answer

Equatorial positions provide more space, minimizing repulsion between lone pairs and bonding pairs.

Question 17

Which of the following is a limitation of Lewis theory?

Accepted Answer

It cannot accurately predict magnetic properties such as paramagnetism in $$\mathrm{O_2$}.$$

Question 18

In molecular orbital theory, what is the result of constructive interference between atomic orbitals?

Accepted Answer

A bonding molecular orbital with lower energy than the original atomic orbitals.

Question 19

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

Accepted Answer

$$\mathrm{CO_2$}$$

Chapter 10: Chemical Bonding II – Molecular Shapes, Valence Bond Theory, and Molecular Orbital Theory

Guida di studio - Domande di pratica

Study guide - Flashcard