Problem 9 - Chemistry The Central Science In Si Units

Question

List the three states of matter in order of (a) increasing molecular disorder and \((\mathbf{b})\) increasing intermolecular attraction. (c) Which state of matter is most easily compressed?

Step-by-Step Solution

Answer

(a) Solid, Liquid, Gas. (b) Gas, Liquid, Solid. (c) Gas is most easily compressed.

Step 1: Understanding Molecular Disorder

Matter exists in three common states: solid, liquid, and gas. Molecular disorder increases from solid, where particles are tightly packed and orderly, to liquid, where they are less orderly but still connected, to gas, where particles are free and highly disordered.

Step 2: Order of Increasing Molecular Disorder

To list the states of matter in order of increasing molecular disorder: 1) Solid, 2) Liquid, 3) Gas. This is because particles in solids have the least freedom to move compared to those in liquids and gases.

Step 3: Understanding Intermolecular Attraction

Intermolecular attraction is strongest in solids where particles attract each other strongly, weaker in liquids, and weakest in gases where particles are far apart.

Step 4: Order of Increasing Intermolecular Attraction

To list the states of matter in order of increasing intermolecular attraction: 1) Gas, 2) Liquid, 3) Solid. Intermolecular attraction increases as you move from a gas to a solid.

Step 5: Comprehensibility and Compression

Gases are the most easily compressed state of matter due to the large spaces between particles, which can be pushed closer together under pressure.

Key Concepts

Molecular Disorder

Understanding molecular disorder involves observing how the particles within different states of matter are organized. In solids, particles are neatly packed into a regular pattern, making them highly ordered.
In liquids, although the particles are still in close proximity, they lack the rigid structure found in solids, allowing them to flow more freely. This results in a moderate degree of molecular disorder.
Lastly, gases exhibit the highest level of molecular disorder, as their particles are spaced far apart and move independently, with no fixed positions.

• Solids: High order, particles are fixed.
• Liquids: Moderate order, particles can move around each other.
• Gases: High disorder, particles move freely.

Understanding this concept helps explain why substances behave differently in their various states.

Intermolecular Attraction

Intermolecular attraction refers to the forces holding particles of a substance together. In solids, these forces are strongest, helping maintain a fixed volume and shape due to the particles being closely bonded.
Liquids possess weaker intermolecular forces than solids, allowing the particles to slide past one another, which enables the liquid to take the shape of its container while maintaining a constant volume.
For gases, intermolecular attraction is the weakest. The particles are far apart and move independently, allowing gases to expand to fill any available volume.

• Solids: Strong attraction, keeps particles fixed.
• Liquids: Moderate attraction, allows flow.
• Gases: Weak attraction, particles move independently.

Intermolecular forces are key in defining the physical properties of a substance in different environments.

Compression of Matter

The ability to compress a substance depends on the spaces between its particles. Solids are the least compressible because their particles are tightly packed and resist further compression.
Liquids are slightly more compressible than solids but still offer significant resistance because the particles, although not as tight as in solids, are still close.
In contrast, gases can be easily compressed. The large empty spaces between the particles in a gaseous state mean they can be packed closer together when pressure is applied, allowing for significant volume reduction.

• Solids: Least compressible, tightly packed particles.
• Liquids: Limited compression, particles close together.
• Gases: Most compressible, large spaces between particles.

Understanding compression is crucial for applications requiring volume and density changes, like in gas storage and transportation.