Question

Are the particles in a gas farther apart or closer together than the particles in a liquid? Use your answer to explain each of the following general observations: (a) Gases are more compressible than liquids. (b) Gases have lower viscosities than liquids. (c) After thorough stirring, all gas mixtures are solutions. (d) The density of a substance in the gas state is lower than in the liquid state.

Short answer

Gas particles are farther apart. Thus, gases are more compressible, less viscous, form homogeneous solutions easily, and have lower density than liquids.

Step-by-step solution

Analyze Particle Arrangement in Gases and Liquids

Particles in a gas are much farther apart compared to particles in a liquid. This larger distance between particles in gases affects various physical properties.

Explain Gas Compressibility

Because gas particles are farther apart, they have more space to be compressed into a smaller volume. In contrast, liquid particles are closer and have less free space, making them less compressible.

Explain Viscosity in Gases and Liquids

Viscosity refers to the resistance of a substance to flow. Since gas particles are farther apart and interact less frequently, gases have lower viscosities compared to liquids, where the closer particles interact more and create higher resistance to flow.

Explain Gas Mixture Homogeneity

In a gas, the large distances between particles and high kinetic energy ensure thorough mixing. Therefore, all gas mixtures form homogeneous solutions after stirring.

Explain Density Difference Between States

Density is defined as mass per unit volume. Since gas particles are farther apart and occupy more volume than liquid particles for the same mass, the density of a substance in the gas state is significantly lower than in the liquid state.

Key concepts

Gas Compressibility

Gases are much more compressible than liquids. This boils down to particle arrangement. In gases, particles are spread far apart because they have lots of space between them. When you apply pressure, these particles can be pushed closer together, reducing the volume significantly.

Conversely, in liquids, particles are already close together. Trying to compress a liquid is like trying to mash up already packed marbles in a jar—you can't really make them take up much less space. That's why we say gases are highly compressible while liquids are not. This concept is crucial in various fields, including hydraulics and pneumatics, where the compressibility of gases and incompressibility of liquids are key principles.

Viscosity Comparison

Viscosity is the measure of a fluid's resistance to flow. We associate higher viscosities with thicker fluids, such as honey, which flow slowly.

In gases, particles are spaced far apart and move rapidly. They don't interact much with each other, which results in lower viscosity. Think of it like people in a spacious room—they can move around easily without bumping into others.

On the other hand, liquids have particles that are much closer together. These particles interact often, bumping into each other and making it harder for them to flow past one another. This interaction increases the liquid's viscosity, explaining why liquids typically flow slower than gases.

Homogeneous Gas Mixtures

Have you ever stirred sugar into tea and noticed how, after some time, it dissolves and spreads out evenly? Gases work similarly, but much quicker and more thoroughly.

Gases have particles that are far apart and move very quickly. This high motion and large distance ensure that when you mix two gases, they will spread out evenly without much effort. Because of this, all gas mixtures after thorough stirring are homogeneous solutions. This principle is used in creating atmospheres for controlled environments and in mixing fuel and air in engines.

Density Difference in States

Density is defined as mass per unit volume. In gases, the large spaces between particles mean that the same mass occupies a larger volume. This results in a much lower density for gases compared to liquids.

Picture a balloon filled with helium. It is very light even though it seems to occupy a lot of space. Now consider a bottle of water. It is heavier and more compact for the same space. This is because water, as a liquid, has particles that are closely packed, increasing its density.

Understanding density difference is foundational for fields like meteorology, which studies how air masses behave and interact, affecting weather patterns. It also helps explain why substances change densities when transitioning between states, such as when water vapor condenses into liquid water.