Question

The particle-level diagram opposite represents the structure of solid KF. Although the molar mass of KCl is greater than that of KF, the density of KCl is actually less than that of KF. Which of the following representations of the structure of KCl best helps to explain this phenomenon?

Answer 1

It appears that you've mentioned a particle-level diagram, but I can't see the diagram you're referring to. However, I can provide some general information that may help explain the phenomenon you're asking about.

In general, the density of a solid depends on both its molar mass and the way its particles are arranged. Even if the molar mass of KCl (potassium chloride) is greater than that of KF (potassium fluoride), it's possible for KCl to have a lower density than KF if the structure of the solid and the arrangement of its particles are different.

The density of a solid is influenced by factors such as the size and mass of its particles, the way these particles are packed together, and the void spaces between them. If the particles in KCl are arranged in a way that creates more open spaces or voids compared to KF, this could lead to a lower density, even with a higher molar mass.

Without seeing the specific representations of the structures you mentioned (A, B, C, D), it's challenging to pinpoint the best explanation based on the diagrams alone. To determine which representation best explains the phenomenon, you would need to consider the arrangement of particles, void spaces, and other factors in the structures of both KCl and KF as depicted in those representations.

Step-by-step explanation:

Answer 2

The density of KF is greater than that of KCl, even though KCl has a greater molar mass. This can be explained by the difference in lattice energy between the two compounds. The higher lattice energy of KF leads to a more tightly packed arrangement of ions, resulting in a higher density.

Step-by-step explanation:

The density of a substance is determined by the mass of its particles and how closely they are packed together. In the case of KCl and KF, even though KCl has a greater molar mass than KF, the density of KCl is actually lower than that of KF. This can be explained by looking at the ionic structures of the two compounds.

In the solid state, KF and KCl both exist as crystal lattices where positive and negative ions are arranged in a repeating pattern. The lattice energy, which is the energy required to break the ionic bonds and separate the ions, plays a role in determining the density of a compound. The greater the lattice energy, the stronger the ionic bonds and the closer the ions are packed together, leading to a higher density.

In the case of KF, the lattice energy is higher than that of KCl. This is because the K+ and F- ions in KF have stronger attractive forces due to their smaller size and higher charges compared to the K+ and Cl- ions in KCl. As a result, the ions in KF are more tightly packed together, leading to a higher density. Despite the higher molar mass of KCl, the lower lattice energy causes the ions in KCl to be less tightly packed, resulting in a lower density compared to KF.