IMFs Review Questions

How is a covalent bond formed?

A covalent bond is formed by the sharing of electrons between two atoms.

How is a hydrogen bond formed?

A hydrogen bond is formed by the dipole-dipole interactions between two polar molecules containing hydrogen bonded to nitrogen, oxygen, or fluorine.

What causes a London dispersion force to occur between two atoms or molecules?

A momentary imbalance of electrons throughout the molecule.

What is the difference between the formation of an ion and the formation of a momentary dipole?

An ion is created by the removal or addition of an electron to an electrically neutral atom, thereby giving it a charge. A momentary dipole is created by the temporary imbalance of electrons within an electrically neutral atom (the atom remains neutral).

What do you think helps neutral atoms and molecules attract each other?

An uneven distribution of electrons at a given moment helps neutral atoms and molecules form dipoles that hold the atoms and molecules together.

In terms of the positive and negative ends of the dipoles, where do attractive forces occur?

Attractive forces occur between one positive and one negative end.

How might dipole-dipole interactions help many molecules attract each other?

Dipoles are held together by the attraction between the oppositely charged ends of the separate molecules for each other.

How are hydrogen bonds and covalent bonds similar?

Hydrogen bonding is an intermolecular force that results from uneven electron sharing within the molecule. Covalent bonding is the sharing of the electrons themselves and happens within the molecule.

How are hydrogen bonds and covalent bonds different?

Hydrogen bonding is intermolecular, and covalent bonding is intramolecular.

What is the difference between intermolecular and intramolecular forces in terms of where they occur on the molecular level?

Intramolecular forces occur within/inside molecules, while intermolecular forces occur between molecules.

Would you expect nonpolar molecules to "stick together" more or less effectively than polar molecules?

Nonpolar molecules would "stick together" less effectively than polar molecules, because they lack the dipole that would enable them to form positive and negative ends that hold together with dipole-dipole interactions.

What causes the dipole in polar covalent molecules?

Uneven sharing of electrons

In terms of the positive and negative ends of the dipoles, where do repulsive forces occur?

Repulsive forces occur between two positive ends or between two negative ends.

How are London dispersion forces different to dipole-dipole interactions?

They are different, because the dipoles in London dispersion forces are only temporary, whereas dipole-dipole interactions involve permanent dipoles in polar covalent molecules.

How are London dispersion forces similar to dipole-dipole interactions?

They are similar because they both involve the attraction of oppositely charged poles toward each other.

How can you tell if atoms are neutral?

They have an equal number of protons and electrons.

What is a molecule with one positively charged end and one negatively charged end?

dipole