Group 2 Flashcards
What happens to the atomic radius down the group?
increases
What happens to the 1st ionisation energy down the group?
decreases because theres more shielding so a weaker attraction between the nucleus and outer electron
What happens to the melting point down the group?
decreases because the size of ion increases so there’s a weaker electrostatic force of attraction between positive ions and delocalised electrons.
What bonding do they have?
metallic
What is the general equation of their reaction with water?
X + 2H2O ~> Mg(OH)2 +H2
What happens to the ROR with water down the group?
increases because there’s more shielding so outer electrons are further from nucleus so are lost more easily
What are observations when reacting with water down the group?
More vigorous fizzing, reactions warm up quicker, less precipitate formed
What is the equation for Mg reacting with steam?
Mg + H2O ~> MgO(s) +H2
What are the observations of Mg reacting with steam?
White flame and white solid
What happens to the solubility in hydroxides down the group?
increases (Mg is a precipitate)
What happens to the pH when reacting with hydroxides down the group?
increase because there are more OH- ions split off from the element when it’s soluble
What is the test for hydroxide ions and the test for magnesium ions?
Magnesium chloride + unknown OR sodium hydroxide + unknown. Produce a white precipitate
What happens to the solubility of sulfates down the group?
decreases (Ba is insoluble)
What is the test for barium ions?
sulfuric acid + solution = white ppt of ions present
What is the test for sulfate ions?
acidified (to remove interfering ions like carbon) barium chloride + solution= white ppt of ions present
