Group 2 Flashcards
What are group 2 metals known as?
The alkaline earth metals.
What ions do group 2 metals react to form?
2+ ions - lose two electrons
What do group 2 elements do in air?
They tarnish and form a coating of the metal oxide
How does the atomic radius of group 2 metals vary down the group?
It increases due to additional electron shells
Why does reactivity of group 2 metals increase down the group?
There is increased electron shielding and increased atomic radius so the outer electrons are easier to lose
How do the 1st and 2nd ionisation energies vary down group 2?
It decreases - greater shielding + atomic radius.
How do group 2 atoms react with water?
In a redox reaction to produce a metal hydroxide and hydrogen.
What does a group 2 metal’s reaction with water form?
An alkaline solution
What kind of agents are group 2 metals?
Reducing agents
What can speed up group 2 metal’s reactions with water?
Steam (provides the reaction with extra energy)
How does the reactivity of group 2 metals with water vary down the group?
Reactivity increases
As you go down group 2, the reactions with water become….
…increasingly vigorous
Is the alkalinity of metal oxides increases down group 2, what also increases?
The solubility of the metal oxides increases
What colour precipitates do group 2 metals form with chlorine gas?
White precipitates
How do the reactions with chlorine gas vary down group 2?
The reactions become more vigorous as the elements become more reactive.
What can strontium and barium form when reacted with excess oxygen and heated?
Peroxides - MO2
What do group 2 metals form when reacted with oxygen?
Metal oxides (MO)
What does the reaction of a group 2 metal and a dilute acid produce?
Bubbles of hydrogen and solutions of metal compounds.
What does the reaction of Group 2 hydroxides with dilute acid form?
(Neutralisation reaction)
A salt and water
How does the solubility of group 2 metals vary down the group?
Increases
What is magnesium hydroxide and calcium carbonate used as because of its alkaline nature and so can neutralise acids?
In medicine as an antacid to treat indigestion
What is calcium hydroxide used for?
In agriculture to neutralise acidic soils
How does the solubility of group 2 sulfate vary down the group?
It decreases down the group
Because barium sulfate is insoluble, how is it used in medicine?
Barium meals - medical tracer so allow internal tissues and organs to be imaged - is toxic for blood but is insoluble so can’t be absorbed into the bloodstream
What is barium chloride used for?
As a test for sulfate ions as it reacts to form barium sulfate which forms a white precipitate when sulfate ions are present.
What are 3 properties of group 2 metals?
- high melting and boiling points
- low density metals
- form colourless white compounds
