Topic 8- Group 2 Elements Flashcards
What is the trend for atomic radius in group 2?
Why is this?
What is the trend for first ionisation energy in group 2?
Why is this?
What is the increased nuclear charge down group 2 outweighed by?
What is the trend for the melting and boiling points down group 2?
What’s trend for metallic bonding down group 2?
What happens to ionic radius of metal ions in group 2 and what is the result?
What is the attraction like between positive nucleus of metal ions and delocalised electrons?
Atomic radius increases down the group
Extra electron shell, outer electron
First ionisation energy decreases down the group
Extra electron shell, outer electron further from nucleus and more shielded
Greater shielding and distance
Melting and boiling points decrease down the group
Metallic bonding gets weaker down the group
Ionic radius of metal ions increases down group so charge density decreases
Weaker attraction between positive nucleus of metal ions and delocalised electrons.
What is the equation for the reaction of magnesium with water?
What is this reaction like in cold water?
What is the equation for the reaction of calcium with water?
What is the equation for the reaction of magnesium with steam?
What is water in this equation?
What are nitrates said to generally be?
What is an example equation for how group 2 hydroxides can be made?
What is an example equation for how group 2 sulphates can be made?
Mg (s) + 2H2O (l) —> Mg (OH)2 (aq) + H2 (g)
Slow in cold water
Ca (s) + 2H2O (l)—> Ca (OH)2 (aq) + H2 (g)
Mg (s) + H2O (g) —> MgO (s) + H2 (g) (in steam)
Water is a gas (steam)
Nitrates are generally soluble
Mg (NO3)2 (aq) + 2NaOH (aq) —> Mg (OH)2 (s) + 2NaNO3 (aq)
Mg (NO3)2 (aq) + Na2SO4 (aq) —> MgSO4 (aq) + 2NaNO3 (aq).
Describe the solubility and give examples of the following group 2 hydroxides:
Magnesium hydroxide
Calcium hydroxide
Strontium hydroxide
Barium hydroxide
Describe the solubility and give examples of the following group 2 sulphates:
Magnesium sulphate
Calcium sulphate
Strontium sulphate
Barium sulphate
Almost insoluble- eg milk of magnesia
Sparingly soluble- limewater
More soluble
Dissolves- strongly alkaline
Magnesium sulphate is soluble
(eg Epsom salts)
Barium sulphate is virtually insoluble
(eg barium meal).
What is used as part of the process of extracting titanium from its ore?
What is the main titanium ore used?
What is the first step of the extraction of titanium?
What is the equation for this?
What is the second step for the extraction of titanium?
What is the equation for this?
Why is the reduction of TiCl4 carried out in an atmosphere of argon?
Magnesium
Titanium (IV) oxide (TiO2)
The oxide is first converted to the chloride by heating with carbon in a stream of chlorine gas
TiO2 (s) + 2C (s) + 2Cl2 (g) —> TiCl4 (l) + 2CO
The TiCl4 is purified by fractional distillation before being reduced by magnesium in a furnace of almost 1000 oC
TiCl4 (l) + 2Mg (s) —> Ti (s) + 2MgCl2 (s)
Because the titanium reacts with oxygen at high temperatures.
How can acidic sulphur dioxide be removed from flue gases?
How is a slurry made?
What is the first equation for this?
What is the second equation for this?
What is the calcium sulphite in this reaction?
By reacting with alkali (called wet scrubbing)
By mixing CaO or CaCO3 with water. It’s then sprayed into the flue gases
CaO (s) + 2H2O (l) + SO2 (g) —> CaSO3 (s) + 2H2O (l)
CaCO3 (s) + 2H2O (l) + SO2 (g) —> CaSO3 (s) + 2H2O (l) + CO2 (g)
A solid waste product (CaSO3).
