Uses of Group 2 Elements Flashcards
Solubility in
Hydroxide (OH-)
Solubility in OH- (single charged ions) increases down group 2
Solubility in SO4 2-
Solubility in SO4 2- (doubly charged negative ions) decreases down group 2
Magnesium hydroxide said to be…
Sparingly soluble
Test for Sulfate Ions
Add acidified barium chloride (BaCl2) to a solution containing sulfate ions.
Forming a white precipitate of barium sulfate
Group 2 compounds and neutralising of acidity:
Calcium hydroxide
Magnesium hydroxide
Calcium hydroxide used in agriculture to neutralise acid soils.
Magnesium hydroxide used in some indigestion tablets as an antacid.
An antacid is a substance that neutralises excess stomach acid
Use of Barium Sulfate
Barium meals.
BaSO4 2- opaque to X-rays. Used to help diagnose problems with oesophagus, stomach or intestines.
A patient swallows barium meal.
This is a suspension of barium sulfate.
Barium sulfate coats the tissues so they show up on x rays showing the structure of the organs
Uses of Magnesium
Describe
Used as part of the process of extracting titanium from its ore.
Main titanium ore (TiO2) first converted to TiCl4 by heating it with carbon in a stream of chlorine gas.
Titanium chloride is then purified by fractional distillation, before ring reduced by magnesium in a furnace of about 1000oC
Uses of Calcium Oxide and Calcium Carbonate
Name of process
Describe
Used to remove acidic sulfur dioxide from flue gases by reacting with alkali.
Wet scrubbing.
Powdered calcium oxide and calcium carbonate can both be used for this.
A slurry is made by mixing either with water.
It’s then sprayed onto the flue gases.
The sulfur dioxide reacts with the alkaline slurry producing solid waste product, calcium sulfite
Two Equations for Wet Scrubbing
CaO + 2H2O + SO2 —> CaSO3 + 2H2O
or
CaCO3 + 2H2O + SO2 —> CaSO3 + 2H2O + CO2
