10-11 F.3 chemistry Individual Project Work Ionic & covalent compound Yuki Yeung 3A (37)

Background information Name of the compound: Magnesium chloride Formula of the compound: MgCl2 Electron diagram: (an ionic compound)

Physical Properties Melting point: 714 °C (987 K) Boiling point: 1412 °C (1685 K) Physical state at room temperature: solid Colour: white or colourless crystalline Density: 2.32 g/cm3 (anhydrous) / g/cm3 (hexahydrate) Solubility in water (20 °C): (anhydrous) 54.3 g/100 ml (hexahydrate) 157 g/100 mL Electrical conductivity: Solid magnesium chloride does not conduct electricity. Liquid magnesium chloride conducts electricity well.

Chemical properties Laboratory preparation Measure the amount of dilute hydrochloric acid and magnesium ribbon according to ratio (2 :1) Drop the magnesium strip into the hydrochloric acid. The overall reaction is Mg(s) + 2HCl(aq) ===> MgCl2(aq) + H2(g) The only product left in solution is MgCl2. Boil or evaporate the solution to dryness in an evaporating dish. MgCl2 is left as white crystals. Warm these to drive off any excess H2O and HCl(g). * Stirring the solution helps to speed up the reaction

Chemical properties Reactivity towards water: Magnesium chloride dissolves in water to give a faintly acidic solution Acidic or basic: Anhydrous magnesium chloride is an acidic salt Oxidizing or reducing: For every magnesium atom oxidized by a loss of two electrons, two chlorine atoms are reduced by a gain of one electron each.

Uses Magnesium chloride has various uses, such as a storage material for hydrogen, manufacturer of textile, paper, fire-proofing agents, cement, refrigeration brine and the production of magnesium. 1. Culinary use Magnesium chloride can be used in cooking. Magnesium chloride acts as an important coagulant used in the preparation of tofu from soy milk. A small amount of magnesium chloride produces softer tofu whereas a larger amount produces firmer tofu. It is also used as an ingredient in bottled mineral water and baby formula milk.

2. Medical and veterinary use Magnesium chloride has been used in pills as supplemental sources of magnesium to help peoplemaintain normal magnesium levels It is also an anaesthetic (a drug that makes a person unable to feel anything) for cephaopods and bivalve Magnesium chloride is used as a feed additive against tumors *should not be taken as a supplement if you have kidney disease

3. Use as an anti-icer and de-icer Liquid magnesium chloride is sprayed on dry pavement prior to precipitation or wet pavement prior to freezing temperatures in winter months to prevent snow and ice from adhering and bonding to the roadway, thus improving highway safety. It also prevents the formation of new ice. 4. Use in dust and erosion control Liquid or powdered magnesium chloride is applied on the top layer of dry soil to control dust and erosion on unimproved roads and in dusty job sites It absorbs moisture from the air and controls the number of small particles from rising into the air..

Potential hazards Magnesium chloride is slightly irritating to eyes, skin and respiratory system. When air is contaminated with magnesium chloride dust, breathing may become difficult If magnesium chloride is ingested, vomiting and diarrhea may occur If a fire heated to 300 °C starts, it emits toxic fumes of chlorine gasPrecaution Keep in a tightly closed container, stored in a cool, dry, ventilated area Wear protective gloves and use safety goggles when handling magnesium chloride

Interesting or special characteristics of the compound Magnesium chloirde is a white powder extracted from seawater after sodium chloride has been removed, and water is evaporated. It is odorless, not flammable.and stable under normal temperature and pressure. Magnesium chloride solutions are bitter in varying degrees It is soluble in ethanol (alchol). Although it can improve the driving condition, it can damage electric utilities by contaminating insulators and causing tracking and arcing across them.

Sources: n=healthhttp:// n=health