Question 1

Which type of hybridization is present in the central carbon atom of methane ($$CH_4$$), and what is the bond angle between the hydrogen atoms?

Accepted Answer

$$sp^3$$ hybridization; $$109.5^{\circ}$$

Question 2

Which of the following statements best explains why all four C-H bonds in methane are identical?

Accepted Answer

Because carbon undergoes $$sp^3$$ hybridization, forming four equivalent orbitals.

Question 3

What is the molecular geometry and polarity of carbon dioxide ($$CO_2$$)?

Accepted Answer

Linear; nonpolar

Question 4

Which hybridization and geometry are associated with a carbon atom that forms a triple bond, as in acetylene ($$C_2H_2$$)?

Accepted Answer

sp; linear

Question 5

How many sigma ($$\sigma) $$and pi ($$\pi) $$bonds are present in ethylene ($$C_2H_4$$)?

Accepted Answer

$$5\ \sigma$$ and $$1\ \pi$$

Question 6

Which of the following molecules is polar due to its molecular geometry and the presence of lone pairs?

Accepted Answer

$$H_2O$$

Question 7

What is the formal charge on the oxygen atom in the hydroxide ion ($$OH^-$$)?

Accepted Answer

$$-1$$

Question 8

Which of the following best describes the hybridization and geometry of the nitrogen atom in ammonia ($$NH_3$$)?

Accepted Answer

$$sp^3$$; trigonal pyramidal

Question 9

A molecule has a central atom with three sigma bonds and one lone pair. What is the expected hybridization and geometry?

Accepted Answer

$$sp^3$$; trigonal pyramidal

Question 10

Which of the following is a correct Lewis structure for formaldehyde ($$CH_2O$$)?

Accepted Answer

A central carbon with two single bonds to hydrogen and a double bond to oxygen

Question 11

Which of the following statements about isomers is correct?

Accepted Answer

Isomers have the same molecular formula but different connectivity of atoms.

Question 12

What is the hybridization of the central atom in $$BF_3$$ and what is the bond angle?

Accepted Answer

$$sp^2$$; $$120^{\circ}$$

Question 13

Which of the following best describes the bonding in acetylene ($$C_2H_2$$)?

Accepted Answer

Each carbon forms two sigma and two pi bonds

Question 14

Which of the following molecules is nonpolar due to its geometry, despite having polar bonds?

Accepted Answer

$$CO_2$$

Question 15

How many lone pairs are present on the oxygen atom in a water molecule ($$H_2O$$)?

Accepted Answer

Two

Question 16

Which of the following is true about the stability of hybrid orbitals compared to pure atomic orbitals?

Accepted Answer

Hybrid orbitals are more stable because they have lower energy.

Question 17

What is the formal charge on the nitrogen atom in the ammonium ion ($$NH_4$$^+$$)?

Accepted Answer

$$0$$

Question 18

Which of the following best describes the geometry and hybridization of the carbon atom in formaldehyde ($$CH_2O$$)?

Accepted Answer

Trigonal planar; $$sp^2$$

Question 19

Which of the following molecules contains a central atom with $$sp^3$$ hybridization and is polar?

Accepted Answer

$$H_2O$$

Hybridization, Lewis Structures, and Molecular Geometry in Organic Chemistry

Study Guide - Practice Questions