Difference Between Arsenic and Arsine

The key difference between arsenic and arsine is that arsenic is a chemical element, whereas arsine is a chemical compound.

Arsine is a gaseous chemical compound that originates from the combination of arsenic and hydrogen atoms. Arsenic usually exists as a metalloid in room temperature, while arsine is a gas that is flammable and toxic.

1. Overview and Key Difference
2. What is Arsenic
3. What is Arsine
4. Side by Side Comparison – Arsenic vs Arsine in Tabular Form
5. Summary

What is Arsenic?

Arsenic is a chemical element having atomic number 33 and chemical symbol As. Usually, it exists as a grey coloured metalloid. Also, this metal naturally exists in different minerals in combination with other elements such as sulfur and metals. However, we can find it as pure elemental crystals as well. Besides, there are several different allotropes of arsenic, but the isotope with the metallic appearance is mostly used in industrial applications. Moreover, arsenic occurs in nature as a monoisotopic metalloid. That means; it has a single stable isotope.

Arsenic is a p-block element. It is located in group 15 and period 4 of the periodic table. The electron configuration of this metalloid is [Ar]3d¹⁰4s²4p³. Furthermore, this metalloid is in a solid-state at room temperature. Upon heating, it can undergo sublimation.

Primarily, arsenic is used as a component in lead alloys. Moreover, it is useful as a dopant in semiconductors. Apart from that, oxide compounds of arsenic are useful in the production of pesticides, herbicides, insecticides, etc. However, it is not that much used now due to its toxic effects.

There are three common allotropic forms of arsenic: grey, yellow and black arsenic. The most common and useful form is grey arsenic. The crystal structure of arsenic is rhombohedral. When considering its magnetic properties, arsenic is diamagnetic. Grey arsenic is a brittle material due to the weak chemical bonding between the layers of the allotrope. It also has a low hardness.

What is Arsine?

Arsine is a gaseous compound having the chemical formula AsH₃. It is an inorganic compound and is flammable and toxic as well. Considering its other properties, the molar mass of it is 77 g/mol. It appears as a colourless gas and has a faint odour. Also, the arsine molecule has trigonal pyramidal geometry. Further, this gas is denser than air and is slightly water-soluble.

Moreover, the conjugate acid of this gas is arsonium. Generally, we consider this compound as a stable compound, because at room temperature, it decomposes very slowly. At higher temperatures, the decomposition is rapid, and it forms arsenic and hydrogen gas. Some other factors such as humidity, light, catalysts, etc. can facilitate the rate of the arsine decomposition.

What is the Difference Between Arsenic and Arsine?

Arsine is a chemical compound derived from the combination of arsenic and hydrogen atoms. Therefore, the key difference between arsenic and arsine is that arsenic is a chemical element, whereas arsine is a chemical compound. Arsenic is a chemical element having atomic number 33 and chemical symbol As. Meanwhile, arsine is a gaseous compound having the chemical formula AsH₃. Besides that, arsenic usually exists as a metalloid in room temperature, while arsine is a gas that is flammable and toxic.

Moreover, arsenic appears as a grey coloured metalloid, but arsine appears as a colourless gas which has a faint odour. So, this is another difference between arsenic and arsine. Also, arsenic is water-insoluble while arsine is slightly water-soluble. And, the crystal structure of arsenic is rhombohedral while the geometry of arsine is trigonal pyramidal.

Summary – Arsenic vs Arsine

Arsine is a chemical compound that derives from the combination of arsenic and hydrogen atoms. The key difference between arsenic and arsine is that arsenic is a chemical element, whereas arsine is a chemical compound.

Reference:

1. “Facts About Arsenic.” LiveScience, Purch, Available here.

Image Courtesy:

1. “Arsen 1a” By Arsen_1.jpg: Original uploader was Tomihahndorf at de.wikipediaderivative work: Materialscientist (talk) – Arsen_1.jpg (CC BY-SA 3.0) via Commons Wikimedia
2. “Arsine” By Benjah-bmm27 assumed (based on copyright claims) – Own work assumed (based on copyright claims) (Public Domain) via Commons Wikimedia