Topic 8- Group 2 Elements Flashcards Preview

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Flashcards in Topic 8- Group 2 Elements Deck (5)
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1
Q

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?

A

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.

2
Q

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?

A

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).

3
Q

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

A

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).

4
Q

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?

A

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.

5
Q

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?

A

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).