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) / 1.569 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 gas
Precaution
•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:
• http://en.wikipedia.org/wiki/Magnesium_chloride
• http://www.ehow.com/search.html?q=magnesium+chloride&ski
n=health
• http://www.jtbaker.com/msds/englishhtml/m0156.htm
• http://www.tutorvista.com/search/magnesium-chloride