Question

What types of intermolecular forces exist in a crystal of ice? How do these forces differ from the types of intermolecular forces that exist in a crystal of solid oxygen?

Short answer

In a crystal of ice, the primary intermolecular forces are hydrogen bonding, a type of dipole-dipole interaction, and dispersion forces. Hydrogen bonding occurs due to highly electronegative oxygen atoms in H₂O molecules attracting hydrogen atoms in neighboring molecules. In contrast, a crystal of solid oxygen consists of non-polar O₂ molecules and only exhibits dispersion forces, which are present in all molecular substances. Thus, the main difference in intermolecular forces between ice and solid oxygen lies in the presence of hydrogen bonding in ice, while only dispersion forces are significant in solid oxygen.

Step-by-step solution

Understand different types of intermolecular forces

There are three main types of intermolecular forces: 1. Dispersion forces (also known as London forces or van der Waals forces), which are caused by temporary fluctuations in electron distribution around molecules. Dispersion forces are present in all molecular substances and they usually increase with an increase in the molecular size. 2. Dipole-dipole forces, which occur between polar molecules when oppositely charged ends of the molecules (dipoles) attract each other. 3. Hydrogen bonding, which is a specific type of dipole-dipole interaction where a hydrogen atom is bonded to a highly electronegative atom like nitrogen (N), oxygen (O), or fluorine (F), and is attracted to another highly electronegative atom in a neighboring molecule. Step 2: Identify intermolecular forces in ice

Find the forces present in a crystal of ice

Ice is a solid form of water, consisting of H₂O molecules. In ice, the hydrogen bonds represent the strongest type of intermolecular forces. The oxygen atom in an H₂O molecule is highly electronegative, attracting the hydrogen atoms in adjacent water molecules and forming a hydrogen bond. In addition to hydrogen bonding, dispersion forces also exist in ice, as they are present in all molecular substances. Step 3: Identify intermolecular forces in solid oxygen

Find the forces present in a crystal of solid oxygen

Solid oxygen consists of O₂ molecules. Since oxygen is a non-polar molecule, the main intermolecular force present in solid oxygen is the dispersion force. As with all molecular substances, dispersion forces are always present due to temporary fluctuations in electron distribution around molecules. Although oxygen is a highly electronegative element, there are no hydrogen bonds in solid oxygen since there are no hydrogen atoms involved in its structure. Step 4: Compare the forces in ice and solid oxygen

Compare intermolecular forces in ice and solid oxygen

In a crystal of ice, the primary intermolecular force is hydrogen bonding, which is a type of dipole-dipole interaction. Additionally, dispersion forces are present in ice as they are in all molecular substances. On the other hand, in a crystal of solid oxygen, the only significant intermolecular force is the dispersion force, as there are no hydrogen bonds or any other type of dipole-dipole interactions because the substance consists of non-polar O₂ molecules.