Group 2 Chemical Properties (Part 2 )

Group 2 chemical properties (chapter 11 -  part 2):
• Group 2 burns in presence of oxygen forming metal oxides
• Group 2 oxides dissolve in water giving alkaline solution
• We can use flame color test to identify group 2 elements
• Beryllium reacts with steam water at high temperature forming beryllium oxides and hydrogen
• Calcium readily reacts with water forming hydroxides and hydrogen
• Group 2 alkalinity of group 2 hydroxides increases down the group due to the increase in solubility
• Solubility of group 2 sulfates decreases down group 2
• All group 2 carbonates are insoluble in water except for Beryllium
• All group 2 reacts with dilute acid forming salt and water
• Except for formed magnesium sulfate salt, group 2 formed sulfates tend to form insoluble layer on carbonate preventing further reaction
• Dilute hydrolylic acid reaction with group 2 forming soluble chloride salts
• Carbonate and nitrate decompose given off metal oxide
• Temperature at which thermal decomposition takes place increases down group 2
Uses of group 2 compounds: Limestone (calcium carbonate):
1- There are many types of limestone that provide useful rocks for building
2- Marble is another form of calcium carbonate used as a building material such as tiles
3- Calcium carbonate also used to make cement:
First step is roasting limestone in lime kiln
At high temp. in the kiln calcium carbonate decomposes to calcium oxide (quicklime) that is roasted and mixed with clay to make cement
Cement can also be mixed with sand and small pieces of rock to make concreter
4- Slaked lime (calcium hydroxide Ca(OH)2):
Used to raise pH of acidic soil because calcium hydroxide is basic it reacts with acids in the soil and neutralize them raising the pH of the soil
5- Magnesium:
a. Soft light metal
b. Magnesium metal can be used an easily-burned substance with a bright light in photographic flash bulbs.
c. Epsom salts (magnesium sulfate):
d. Relieves pain and muscle cramp
6- Group 2 salts and fireworks:
• Barium - Barium is used to create green colors in fireworks and it can also help stabilize other volatile elements.
• Calcium - Calcium is used to deepen firework colors. Calcium salts produce orange fireworks.
• Magnesium - Magnesium burns a very bright white, so it is used to add white sparks or improve the overall brilliance of a firework.
• Strontium - Strontium salts impart a red color to fireworks. Strontium compounds are also important for stabilizing fireworks mixtures.
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