9.Group 2, the alkaline earth metals Flashcards
What is the general reaction for a metal (M) with water
M (s) + 2H20 (l) —-> M(OH)2 (aq) + H2 (g)
Name a use of magnesium hydroxide
Remedies for heartburn and indigestion
What is the equation for the reaction of magnesium and steam
Mg (s) + H2O (g) —-> MgO (s) + H2 (g)
Describe the trend in the solubilities of the hydroxides
Going down group two, metal hydroxides become more soluble
What is the most and least soluble hydroxide
least: magnesium hydroxide
most: barium hydroxide
Describe the trend in solubilities of metal sulfates
Going down group two, metal sulphates become less soluble
What is the most and least soluble hydroxide sulfate
least: barium hydroxide
most: magnesium hydroxide
Describe a use of barium sulfate
Used in x-rays. Barium meal is insoluble so outlines the gut
Describe a simple test for sulfate ions in a solution
- acidify solution with nitric or hydrochloric acid
- add barium chloride
- if sulfate is present white precipitate of barium sulfate is formed
What is the ionic equation for the sulfate ion test
Ba 2+ (aq) + SO4 2- (aq) —-> BaSO4 (s)
What is the ionic equation for when you dissolve barium hydroxide in water
Ba(OH)2 (s) + aq —-> Ba2+ (aq) + 2OH- (aq)
Why must you acidify the sample in the sulfate ion test
The addition of acid removes carbonate ions as carbon dioxide. Barium carbonate is also a white insoluble solid which would be indistinguishable from barium sulfate
Name a use of calcium hydroxide
Used to treat acidic soil for crops
How is titanium extracted
- usual carbon + metal oxide method cannot be used as TiC is formed
- TiO is first reacted with chlorine and carbon to make TiCl4 and CO
- TiCl4 is reduced to titanium by a reaction with magnesium
What is the equation for the reduction of of TiCL4 by a reaction with magnesium
TiCl4 (l) + 2Mg (s) —-> 2MgCl2 (s) + Ti (s)
