Question 1

The image shows a group of bees clustered together. According to the study materials, what chemical mechanism allows the queen bee to control the behavior of worker bees?

Accepted Answer

By releasing a pheromone that acts as a chemical messenger

Question 2

Which concept from VSEPR theory is most closely related to the way enzymes and receptor proteins interact with other molecules, as described in the study materials?

Accepted Answer

Molecular geometry determines specificity, similar to a lock-and-key mechanism

Question 3

What is the main idea behind the VSEPR theory as described in the study materials?

Accepted Answer

Electron pairs around a central atom arrange themselves as far apart as possible to minimize repulsion

Question 4

Which of the following best describes the three-dimensional structure of methane, CH$$_4$$, according to VSEPR theory?

Accepted Answer

Tetrahedral with bond angles of $$109.5^{\circ}$$

Question 5

A molecule of water, H$$_2O$$, has two lone pairs on the central oxygen atom. What is the resulting bond angle between the hydrogen atoms?

Accepted Answer

$$104.5^{\circ}$$

Question 6

Which of the following molecules has a trigonal planar structure according to VSEPR theory?

Accepted Answer

BF$$_3$$

Question 7

What is the predicted geometry and bond angle for beryllium chloride, BeCl$$_2$$, using VSEPR theory?

Accepted Answer

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

Question 8

Which of the following best explains why the bond angle in ammonia, NH$$_3$$, is $$107^{\circ}$$ instead of $$109.5^{\circ}$$?

Accepted Answer

The lone pair on nitrogen repels the bonding pairs more strongly, decreasing the bond angle

Question 9

Which of the following molecules has a trigonal bipyramidal structure?

Accepted Answer

PCl$$_5$$

Question 10

When using VSEPR theory to predict the shape of a molecule with multiple bonds, such as CO$$_2$$, how should you treat the double bonds?

Accepted Answer

Treat each multiple bond as a single group of electrons

Question 11

Which of the following best describes the three-dimensional structure of SF$$_6$$?

Accepted Answer

Octahedral with bond angles of $$90^{\circ}$$

Question 12

Which of the following is a limitation of the VSEPR theory as described in the study materials?

Accepted Answer

It does not always accurately predict bond angles, as seen in PH$$_3$$

Question 13

Which of the following steps is NOT part of the VSEPR approach for predicting molecular shape?

Accepted Answer

Maximize the attraction between nuclei

Question 14

What is the three-dimensional structure of the ammonium ion, NH$$_4^+$$, according to VSEPR theory?

Accepted Answer

Tetrahedral

Question 15

Which of the following molecules would you expect to have a bent structure due to the presence of lone pairs on the central atom?

Accepted Answer

H$$_2O$$

Question 16

A molecule has four electron pairs around the central atom, two of which are lone pairs. What is the name of the structure and the most common bond angle?

Accepted Answer

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

Question 17

Which of the following best describes the arrangement of electron pairs in a molecule with a square planar structure?

Accepted Answer

Four bonding pairs and two lone pairs around the central atom

Question 18

Which of the following molecules has a trigonal pyramidal structure due to the presence of a lone pair on the central atom?

Accepted Answer

NH$$_3$$

Question 19

Which of the following is a real-world application of molecular geometry as described in the study materials?

Accepted Answer

Enzyme specificity in biological systems

Question 20

Which of the following statements about lone pairs and molecular shape is correct according to VSEPR theory?

Accepted Answer

Lone pairs are not included in the name of the molecular shape but do affect bond angles

Lesson 4.2: Three-Dimensional Structure and VSEPR Theory in Chemistry

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Study guide - Flashcard