8.1 Group 2 Flashcards
What is the alternative name for the group 2 elements?
Alkaline Earth metals
Describe the outer electron position of all group 2 elements.
2 outer electrons are always in the outer S2 subshell.
Are group 2 elements oxidising or reducing agents? Why?
Reducing agents. The atoms lose 2 electrons to form a +2 charge, and another species gain these 2 lost electrons, and are reduced.
How does the pattern of being a reducing agent change going down group 2?
Stronger reducing agents going down the group
What do all group 2 elements react with oxygen to form?
Metal oxides with formula MO
What do all group 2 elements react with water to form?
An alkaline hydroxide with formula M(OH)2
How does the pattern of reacting with water change going down group 2?
React more vigorously with water going down the group
Going down group 2, how does reactivity change?
Reactivity increases going down the group.
Explain how reactivity changes going down group 2.
-Ionisation energies decrease because:
-Atomic radius increases
-Electron shielding increases
-Nuclear charge increases
-So overall, the attraction between the nucleus and outer electrons decreases.
How do group 2 oxides react with water?
They release OH- ions, and form alkaline solutions of the metal hydroxide
What happens when the alkaline solutions of a group 2 metal and hydroxide ions become saturated?
Any further metal and hydroxide ions will form a solid precipitate
How does the solubility of hydroxides change going down group 2?
Solubility increases going down the group.
Why does alkalinity of group 2 hydroxide solutions in water increase going down the group?
Because solubility of group 2 metal hydroxides increases, resulting solutions contain more OH- ions, and are therefore more alkaline.
State the trends of Group 2 hydroxides that occur going down the group.
-Solubility increases
-pH increases
-Alkalinity increases
State the trends of Group 2 elements that occur going down the group.
-Ionisation energy decreases
-Reactivity increases
-Stronger reducing agents
-React more vigorously with water
What is the key use of Calcium Hydroxide?
Added to fields to increase the pH of acidic soils
What are the key uses for Group 2 bases?
Antacids for treating acid indigestion. Neutralise acids.
