Topic 4 Flashcards
What is the equation for the reaction of a Group 2 metal with water?
M (s) + 2H2O (l) —) M(OH)2 (aq) + H2 (g)
What is the equation for the reaction of Group 2 metals burning in oxygen?
2M (s) + O2 (g) —) 2MO (s)
MO is a solid white oxide
What is the equation for the reaction of Group 2 metals with chlorine?
M (s) + Cl (g) —) MCl2 (s)
MCl2 is a solid white chloride
What is the reactivity of Group 2 metals with water as you go down the group?
Be doesn’t react
Mg VERY slow
Ca steadily
Sr fairly quickly
Ba rapidly
What happens to the ionisation energy of Group 2 metals as you go down the group and why?
Decreases.
Extra electron shells
Shield the outer electrons from the attraction of the nucleus
And means that the outer electrons are further away from the nucleus
Outweighs increasing nuclear charge
Reduces electrostatic attraction between nucleus and outer electrons
What does the reaction of Group 2 metal oxides with water form?
Metal hydroxides
How do the hydroxide ions, OH-, in Group 2 metal hydroxides affect the solution?
They make it strongly alkaline
Does beryllium oxide react with water?
No
Is beryllium hydroxide soluble?
No
What is the equation for the reaction of a Group 2 metal oxide with water?
MO (s) + H2O (l) —) M(OH)2 (aq)
What is the equation for the reaction of a Group 2 metal oxide with dilute hydrochloric acid?
MO (s) + 2HCl (aq) —) MCl2 (aq) + H2O (l)
How does the solubility of compounds of Group 2 metals containing singly charged negative ions (e.g. OH-) change down the group?
Increases
How does the solubility of compounds of Group 2 metals containing doubly charged negative ions (e.g. SO4^2-) change down the group?
Decreases
Which Group 2 metal sulphate is insoluble?
Barium sulphate
What is thermal decomposition?
When a substance breaks down when heated. The more thermally stable a substance is, the more heat it will take to break it down.