Group 2 Flashcards
(9 cards)
1
Q
What are group 2 metals?
A
- alkaline earth metals
- alkaline properties of the metal hydroxide they form
- reactive metals and do not occur in their elemental form naturally
- beryllium behaves differently
2
Q
How do group 2 oxides react with water?
A
SrO(s) + H20(l) ———> Sr(OH)2(aq)
3
Q
How soluble are the group 2 hydroxides?
A
- only slightly soluble in water
- when dissolve they dissociate to realise the metal cation and the hydroxide ion
Ca(OH)2 + aq ———> Ca2+(aq) + 2OH-(aq)
- solubility of hydroxides increase down the group?
4
Q
What is the trend going down the group 2 hydroxides?
A
- solubility increases
- pH (8-14) increases
- alkalinity increases
5
Q
What is the use of Ca(OH)2 and why?
A
USE = agriculture
REASON = neutralises acidic soils
6
Q
What is the use of Mg(OH)2 and CaCO3 and why?
A
USE = ‘milk of magnesia’ to treat indigestion
REASON = neutralises excess stomach acid (HCl)
7
Q
What is the melting/boiling point and the conductivity of the group 2 metals?
A
- high melting and boiling points due to strong metallic bonds in their giant metallic lattice structures
- can conduct electricity in both solid and molten phases due to the mobile delocalised electrons
8
Q
Why are group 2 metals considered s-block elements?
A
Because their outermost, highest energy electron is in the s-sub shell
9
Q
How does magnesium react with water?
A
- reaction with liquid water is very slow
- reacts much more vigorously with steam
- magnesium hydroxide produced thermally decomposes to form magnesium oxide
