The key difference between halogen and metal halide is that a halogen is a group 17 chemical element, whereas metal halide is a compound containing a metal and a halogen.
Metal halides are ionic or covalent compounds of halogens. A halogen is a chemical element and all the elements in the group 17 of the periodic table are known as halogens generally.
CONTENTS
1. Overview and Key Difference
2. What is Halogen
3. What is Metal Halide
4. Side by Side Comparison – Halogen vs Metal Halide in Tabular Form
5. Summary
What is Halogen?
Halogens are group 17 chemical elements in the periodic table. The group contains five chemical elements, including Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (At). Often we use the symbol X to symbolize a halogen. The term halogen refers to “salt producing”. That means; these chemical elements tend to form salts when reacting ng with metals. A reaction between a halogen and a metal produces a wide range of salt compounds. The halogen group contains elements that exist in different phases of matter. For example, fluorine and chlorine are gases, while bromine is a liquid and iodine is a solid at room temperature.
Figure 01: Chlorine, Bromine and Iodine
Down the group of halogens in the periodic table, reactivity decreases, size of an atom increases, electronegativity decreases, the phase of matter changes from a gas to solid, etc. When considering the uses of the halogens, they are useful as disinfectants, important for halogen lamps, useful as ingredients in some drugs, etc.
What is a Metal Halide?
Metal halides are ionic or covalent compounds of metals and halogens. Some covalent metal halide compounds occur as either discrete molecules or as polymeric structures. All the halogens tend to react with metals, forming metal halides.
Figure 02: Structure of the Metal Halide Antimony Fluoride
Theoretically, we can produce a metal halide via the reaction between the chemical elements, but this type of reaction is highly exothermic practically. Therefore, we can use some other methods such as neutralization reaction of metal oxides and hydroxides.
When considering the properties, ionic metal halides are highly stable; thus, they tend to have high melting and boiling points. However, these compounds freely dissolve in water. Some compounds are deliquescent as well. But, they are poorly soluble in organic solvents. Moreover, discrete metal halide molecules have comparatively low melting and boiling points.
What is the Difference Between Halogen and Metal Halide?
The key difference between halogen and metal halide is that a halogen is a Group 17 chemical element, whereas metal halide is a compound containing a metal and a halogen. In other words, a halogen is a chemical element while metal halide is a chemical compound.
Moreover, a further difference between halogen and metal halide is that a halogen can exist in different phases of matter, including fluorine and chlorine in the gas phase, bromine in the liquid phase, and iodine in the solid phase, but metal halides exist in the solid phase.
Summary – Halogen vs Metal Halide
In summary, the key difference between halogen and metal halide is that a halogen is a Group 17 chemical element, whereas metal halide is a compound containing a metal and a halogen. Basically, halogen is a chemical element while metal halide is a chemical compound.
Reference:
1. “Halogen.” Wikipedia, Wikimedia Foundation, 30 June 2019, Available here.
Image Courtesy:
1. “Halogens” By W. Oelen – Science Made Alive: Chemistry/Elem – HalogensTransferred from en.wikipedia to Commons by User:ТимофейЛееСуда using CommonsHelper (CC BY-SA 3.0) via Commons Wikimedia
2. “PAntimony-pentafluoride-2D” (Public Domain) via Commons Wikimedia
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