Question 1

Which of the following statements best explains why two compounds with the same molecular formula can have different physical properties such as boiling point?

Accepted Answer

They are constitutional isomers, meaning they have different connectivity of atoms.

Question 2

Which of the following best describes a covalent bond?

Accepted Answer

A pair of electrons shared between two atoms.

Question 3

What is the formal charge on the oxygen atom in the molecule $$H_2CO ($$formaldehyde), given that oxygen has 6 valence electrons, is bonded to carbon with a double bond, and has two lone pairs?

Accepted Answer

$$0$$

Question 4

Which of the following bonds is expected to be the most polar based on electronegativity differences?

Accepted Answer

$$C-F$$

Question 5

A molecule has a steric number of 3 and no lone pairs on the central atom. What is its expected geometry and hybridization?

Accepted Answer

Trigonal planar, $$sp^2$$ hybridization

Question 6

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

Accepted Answer

A $$\sigma$$ bond is stronger than a $$\pi$$ bond because it results from head-on overlap of orbitals.

Question 7

Which of the following molecules is capable of hydrogen bonding with itself?

Accepted Answer

$$CH_3OH$$

Question 8

Which of the following best explains why nonpolar molecules such as $$C_6H_{14} ($$hexane) have higher boiling points as their molecular mass increases?

Accepted Answer

London dispersion forces increase with molecular mass and surface area.

Question 9

Which of the following solvents is considered protic and can participate in hydrogen bonding?

Accepted Answer

Acetic acid

Question 10

A soap molecule is able to remove grease from clothing because:

Accepted Answer

It has both a polar (hydrophilic) head and a nonpolar (hydrophobic) tail, allowing it to form micelles around nonpolar dirt.

Question 11

Which of the following best describes the molecular orbital theory's explanation for bond formation?

Accepted Answer

Atomic orbitals combine to form molecular orbitals that extend over the entire molecule, with electrons occupying the lowest energy orbitals available.

Question 12

Which of the following molecules would have a net dipole moment of zero?

Accepted Answer

$$CO_2$$

Question 13

Which of the following statements about hybridization is correct?

Accepted Answer

An $$sp^3$$ hybridized carbon forms four sigma bonds with tetrahedral geometry.

Question 14

Which of the following best explains why water ($$H_2O) $$has a higher boiling point than methane ($$CH_4$$)?

Accepted Answer

Water molecules form hydrogen bonds, which are much stronger than the London dispersion forces in methane.

Question 15

Which of the following is the correct electron configuration for a neutral carbon atom?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^2$$

Question 16

Which of the following best describes the effect of branching on the boiling point of alkanes?

Accepted Answer

Increased branching decreases the boiling point due to reduced surface area and weaker London dispersion forces.

Question 17

Which of the following is a correct statement about the relationship between bond length and hybridization in carbon-carbon bonds?

Accepted Answer

$$sp^3-sp^3$ bonds are longer than sp^2$-sp^2$$ bonds, which are longer than $$sp-sp$$ bonds.

Question 18

A molecule has the formula $$C_2H_2 ($$acetylene). What is the hybridization of each carbon atom and the geometry around each carbon?

Accepted Answer

Each carbon is $$sp$$ hybridized with linear geometry.

Question 19

Which of the following best explains why DNA forms a double helix structure?

Accepted Answer

Hydrogen bonding between complementary base pairs stabilizes the double helix.

Chapter 1: Review of General Chemistry – Electrons, Bonds, and Molecular Properties

Guida di studio - Domande di pratica

Study guide - Flashcard