Question 1

Which of the following statements about Lewis structures is CORRECT?

Accepted Answer

The total number of valence electrons in the molecule must be accounted for in the Lewis structure.

Question 2

What is the formal charge on the central nitrogen atom in the ammonium ion ($$\mathrm{NH_4$^+}$$)?

Accepted Answer

$$+1$$

Question 3

Which molecule below is an example of a hypervalent compound?

Accepted Answer

$$\mathrm{SF_6$}$$

Question 4

Given the Lewis structure for water ($$\mathrm{H_2O}$$), what is the AXE notation and the molecular geometry?

Accepted Answer

AX2E2, Bent

Question 5

Which of the following best describes the relationship between bond order, bond length, and bond strength?

Accepted Answer

As bond order increases, bond length decreases and bond strength increases.

Question 6

What is the total number of valence electrons in the carbonate ion ($$\mathrm{CO_3$^{2-}}$$)?

Accepted Answer

$$24$$

Question 7

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

Accepted Answer

$$\mathrm{CO_2$}$$

Question 8

What is the average bond order for each C–O bond in the carbonate ion ($$\mathrm{CO_3$^{2-}}$$)?

Accepted Answer

$$1\frac{1}{3}$$

Question 9

Which of the following best explains why the Lewis structure for $$\mathrm{SF_6$} is $$possible, even though sulfur appears to have more than eight electrons?

Accepted Answer

Sulfur is in the third period and can expand its octet using d orbitals.

Question 10

Which of the following molecules has a trigonal bipyramidal electron geometry?

Accepted Answer

$$\mathrm{$$PCl_5$$}$$

Question 11

Which atom is the most electronegative according to the Pauling scale?

Accepted Answer

Fluorine

Question 12

What is the formal charge on each oxygen atom in one resonance structure of $$\mathrm{CO_3$^{2-}}$$ where two oxygens are single-bonded and one is double-bonded to carbon?

Accepted Answer

-1, -1, 0

Question 13

Which molecule below has a bond angle closest to $$109.5^\circ$$?

Accepted Answer

$$\mathrm{CH_4$}$$

Question 14

Which of the following best describes the geometry and polarity of ammonia ($$\mathrm{NH_3$}$$)?

Accepted Answer

Trigonal pyramidal, polar

Question 15

A molecule has the AX3E notation. What is its molecular geometry?

Accepted Answer

Trigonal pyramidal

Question 16

Which of the following is a correct statement about resonance structures?

Accepted Answer

The actual structure is a hybrid of all resonance forms.

Question 17

Which of the following molecules is expected to be polar due to its geometry, even though its bonds are identical?

Accepted Answer

$$\mathrm{H_2O}$$

Question 18

What is the underlying electron geometry and molecular geometry for the central atom in $$\mathrm{SF_4$}$$?

Accepted Answer

Trigonal bipyramidal, see-saw

Question 19

Which of the following best explains why propane ($$\mathrm{C_3H_8}) is $$nonpolar?

Accepted Answer

It contains only nonpolar bonds and has a symmetrical geometry.

Question 20

Which of the following is the correct electron configuration for magnesium using noble gas notation?

Accepted Answer

$$[\mathrm{Ne}]3s^2$

Lewis Structures and Molecular Geometry: A Comprehensive Study Guide

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