Question

Choose one of the following terms to match the definition or description given. a. alloy b. specific heat c. crystalline solid d. dipole-dipole attraction e. equilibrium vapor pressure f. intermolecular g. intramolecular h. ionic solids i. London dispersion forces j. molar heat of fusion k. molar heat of vaporization I. molecular solids m. normal boiling point n. semiconductor forces between molecules in a solid

Short answer

The correct term that matches the definition or description "forces between molecules in a solid" is (f) intermolecular.

Step-by-step solution

Analyze the terms

Understand the meaning of each term to identify the correct match: a. alloy: A mixture of two or more elements, at least one of which is a metal. b. specific heat: The amount of heat required to raise the temperature of one unit of a substance by one degree. c. crystalline solid: A solid with a highly regular arrangement of atoms, ions, or molecules. d. dipole-dipole attraction: The attractive forces between the positive end of one polar molecule and the negative end of another polar molecule. e. equilibrium vapor pressure: The pressure exerted by a vapor in equilibrium with its liquid or solid phase. f. intermolecular: Existing or occurring between molecules. g. intramolecular: Existing or occurring within a molecule. h. ionic solids: A solid made up of oppositely charged ions held together by electrostatic forces. i. London dispersion forces: Weak attractive forces between nonpolar molecules resulting from temporary dipoles. j. molar heat of fusion: The amount of heat required to convert one mole of a solid into a liquid without any change in temperature. k. molar heat of vaporization: The amount of heat required to convert one mole of a liquid into a gas without any change in temperature. l. molecular solids: A solid composed of molecules held together by non-covalent interactions. m. normal boiling point: The temperature at which the vapor pressure of a liquid equals to atmospheric pressure. n. semiconductor: A material that has electrical conductivity between that of a conductor and an insulator.

Identify the matching term

Now that we've gone over the different terms and their meanings, the forces between molecules in a solid refers to the attractive forces acting between molecules in the solid state. From the definitions above, we can see that the term "intermolecular" (f) matches this description, as it is defined as existing or occurring between molecules. So, the correct answer is: f. intermolecular

Key concepts

Intermolecular Forces

Understanding intermolecular forces is crucial for students studying chemistry or physics as it explains how molecules interact with each other. These are the forces that hold molecules together in a substance and play a key role in determining the physical properties of compounds, such as boiling points, melting points, and solubilities.

Intermolecular forces can be categorized into several types, such as London dispersion forces, dipole-dipole attraction, and hydrogen bonding. These forces vary in strength but are generally weaker than the intramolecular forces that hold atoms together within a molecule, such as covalent or ionic bonds.

Recognizing the relationship between the state of matter (solid, liquid, or gas) and intermolecular forces is important. In solids, these forces are strong enough to keep molecules closely packed together in a fixed position, whereas in liquids, the molecules are close but can move past each other due to weaker intermolecular forces.

London Dispersion Forces

London dispersion forces are a type of intermolecular force that exists between all molecules, regardless of whether they are polar or nonpolar. These forces are also known as van der Waals forces, after the scientist who first proposed their existence.

They are the weakest of all intermolecular forces and arise due to the momentary uneven distribution of electrons within molecules, creating a temporary dipole. This transient dipole can induce a corresponding dipole in a neighboring molecule, leading to an attraction between the two.

The strength of London dispersion forces increases with the size of the molecules because larger molecules have more electrons, which can lead to greater fluctuations in electron distribution. These forces are significant in nonpolar substances like noble gases and nonpolar organic compounds.

Dipole-Dipole Attraction

Dipole-dipole attraction is another variety of intermolecular force, specifically between polar molecules. When a molecule is polar, it has a region with a partial positive charge and another with a partial negative charge, effectively making it a dipole.

The positive end of one polar molecule is attracted to the negative end of another, which aligns the molecules in such a way that they experience an electrostatic attraction. These interactions are stronger than London dispersion forces but weaker than ionic or covalent bonds.

Dipole-dipole attractions contribute significantly to the physical properties of polar substances. For example, they are the reason why water has a relatively high boiling point for a small molecule.

Molecular Solids

Molecular solids are substances where the constituent particles are molecules held together by intermolecular forces rather than intramolecular forces. These solids are generally characterized by their relatively low melting and boiling points because the intermolecular forces maintaining the solid structure are weak compared to the bonds within molecules.

The typical intermolecular forces in molecular solids are London dispersion forces, dipole-dipole attractions, and sometimes hydrogen bonding. Since these forces are weaker than metallic or ionic bonds, molecular solids tend to be softer and have lower densities.

Examples of molecular solids include ice (solid water), dry ice (solid carbon dioxide), and molecular crystals like sugar and solid iodine.