Magnesium Chemistry
Magnesium burns with a bright white flame and is essential in chlorophyll.
Magnesium burns with a bright white flame and is essential in chlorophyll.
Magnesium is a light Group 2 metal, protected by a thin oxide film in air, that burns with a dazzling white flame. It reacts with steam and dilute acids to release hydrogen, and it forms MgO when burned. Mg2+ is the central ion of chlorophyll, where it sits in a porphyrin-like ring and helps capture light energy. Magnesium is also a cofactor for many enzymes that use ATP. Its alloys with aluminium are used in lightweight car parts and aircraft because they combine low density with reasonable strength.
Key ideas: Mg burns with brilliant white light: 2Mg + O2 gives 2MgO. It also forms Mg3N2 in air, and Mg3N2 + 6H2O gives 3Mg(OH)2 + 2NH3. Mg(OH)2 (milk of magnesia) is an antacid; MgSO4.7H2O is Epsom salt. Mg is in chlorophyll at the center of the porphyrin ring. Industrial extraction is by electrolysis of molten MgCl2 from seawater or the Pidgeon silicon reduction.
Common mistakes and connections: Students think Mg reacts quickly with cold water; it reacts only slowly, but readily with steam. Magnesium fires cannot be put out with water or CO2, which reacts with hot Mg. Mg2+ hydrolyzes less than Be2+ and Al3+. Links to alkaline earth trends, chlorophyll and Grignard reagents.
Magnesium has two 3s valence electrons and gives Mg2+, the central ion in chlorophyll; burning in air forms white MgO. The interactive lesson shows this as a live animation or chart.
Burning a magnesium ribbon produces a bright white light and a white powder of magnesium oxide.
Magnesium burns with a bright white flame and is essential in chlorophyll.
Magnesium Chemistry is a intermediate topic in Inorganic Chemistry. It builds on the vocabulary of beginner topics in this area.
Study these earlier topics in Inorganic Chemistry first: Calcium Compounds, Plaster of Paris, Cement.
The next topics in Inorganic Chemistry are Boron Family and Borax.
Yes. The interactive lesson includes a self-check question on Magnesium Chemistry, and the Inorganic Chemistry quiz draws on every topic in this area.
Magnesium Chemistry is topic 17 of 113 in Inorganic Chemistry.