The key difference between sodium aluminate and sodium meta aluminate is that sodium aluminate is an oxide compound, whereas sodium meta aluminate is a hydroxide compound.
Sodium aluminate is an inorganic compound. It is an oxide which has sodium cations combined with aluminium oxide anions. This compound is also called sodium ortho aluminate. Sodium meta aluminate, on the other hand, is a derivative of sodium aluminate.
CONTENTS
1. Overview and Key Difference
2. What is Sodium Aluminate
3. What is Sodium Meta Aluminate
4. Side by Side Comparison – Sodium Aluminate vs Sodium Meta Aluminate in Tabular Form
5. Summary
What is Sodium Aluminate?
Sodium aluminate is an inorganic chemical compound having the chemical formula NaAlO2. This chemical compound is very useful in both industrial and laboratory applications as a source for the production of sodium hydroxide.
Figure 01: Sodium Aluminate
Pure sodium aluminate is an anhydrous compound that appears as a white crystalline solid. The hydrated sodium aluminate occurs as a hydroxide compound; the most common hydrated sodium aluminate form is the tetrahydroxyaluminate of sodium. Its chemical formula is NaAl(OH)4. The anhydrous sodium aluminate has the structure of a 3D framework containing AlO4 tetrahedra with corners linked to each other.
We can obtain the commercially available sodium aluminate in the form of a solution or as a solid compound. This substance is highly hygroscopic. When sodium aluminate is dissolved in water, it gives a black coloured colloidal solution. Sodium aluminate is odourless.
We can manufacture sodium aluminate via dissolution of aluminium hydroxide in caustic soda. Using a concentrated caustic soda solution forms the semi-solid product. Therefore, it is important to choose the correct concentration required for the reaction. The reaction is carried out in vessels made of nickel or steel that are steam-heated.
There are several important uses of sodium aluminate substance: in water treatment systems for water softening, to accelerate solidification in the construction field, in the paper industry, in fire brick production, alumina production, etc.
What is Sodium Meta Aluminate?
Sodium meta aluminate is the hydrated form of sodium aluminate. Therefore, sodium meta aluminate mainly occurs in the form of hydroxide. We call it sodium tetrahydroxide. This is because it has the chemical formula NaAl(OH)4. The anhydrous form of this compound is sodium aluminate.
Figure 02: Chemical Structure of Tetrahydro Aluminate Ion. This ion, in combination with a sodium cation, forms sodium meta hydroxide compound.
Sodium meta aluminate forms when two water molecules are associated with sodium aluminate chemical compound. Therefore, it is a dihydrated form. Normally, AlO2– ion is called “meta” while the AlO33- ion is called the “ortho” compound. The ortho, para and meta conformations of aluminate ions differ from each other depending on the condensation degree. The term “meta” refers to the least hydrated form of sodium aluminate.
What is the Difference Between Sodium Aluminate and Sodium Meta Aluminate?
The key difference between sodium aluminate and sodium meta aluminate is that sodium aluminate is an oxide compound, whereas sodium meta aluminate is a hydroxide compound. The chemical formula of sodium aluminate is NaAlO2 while the chemical formula of sodium meta aluminate is NaAl(OH)4. Sodium meta aluminate is actually a derivative of sodium aluminate.
Below infographic tabulates the differences between sodium aluminate and sodium meta aluminate.
Summary – Sodium Aluminate vs Sodium Meta Aluminate
Sodium aluminate is an inorganic chemical compound having the chemical formula NaAlO2. Sodium meta aluminate is a derivative of sodium aluminate. The key difference between sodium aluminate and sodium meta aluminate is that sodium aluminate is an oxide compound, whereas sodium meta aluminate is a hydroxide compound.
Reference:
1. “Aluminium Sodium Tetrahydroxide.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, Available here.
2. Jakhar, Simran. “Simran Jakhar.” Askiitians Discussion Board, 8 Aug. 2016, Available here.
3. “Sodium Aluminate.” Wikipedia, Wikimedia Foundation, 19 Jan. 2020, Available here.
Image Courtesy:
1. “NaAlO2” By Leiem – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Tetrahydroxoaluminate ion” By Leyo – Own work (Public Domain) via Commons Wikimedia