Name: Internal Energy
Uploaded: 2019-07-19
Duration: 14 min 36 s
Description: In this video, we will learn about the internal energy of a thermodynamic system, and it depends only on temperature, which is due to the kinetic energy of gas molecules.

Question

Chlorine, bromine and iodine are all halogen elements with many properties in common. At room temperature chlorine is a gas, bromine is a dark liquid (although it readily produces a brown vapour) and iodine is a crystalline solid. How do these three states differ from each other?

Accepted Answer

The melting/boiling point of a substance determines the state of matter it takes at a certain temperature.

In ${Cl}_{2}$ , there are covalent bonds between the atoms forming simple molecules. There are weak attractions between molecules of ${Cl}_{2}$ , meaning little energy is needed to break these forces of attraction and therefore ${Cl}_{2}$ has a low boiling point.

Bromine is a liquid because electrons are well apart from the nuclei, so they are easily distorted. Intermediate intermolecular forces exists, and thus it is in liquid state.

The magnitude of Van der Waal forces of attraction is very large due to larger molecular size, so iodine is solid at room temperature.

Gary Horner Solutions for Chapter: Energy, Exercise 11: Exercise 11

Gary Horner Chemistry Solutions for Exercise - Gary Horner Solutions for Chapter: Energy, Exercise 11: Exercise 11

Questions from Gary Horner Solutions for Chapter: Energy, Exercise 11: Exercise 11 with Hints & Solutions

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