inorganic 1 - group 2 metals Flashcards
write an equation for the first ionisation energy of magnesium?
Mg (g) —-> Mg+(g) + e-
what happens to the first ionisation energy as you go down group 2?
decreases because:
- number of filled electron shells increases down the group
- increased shielding = increased atomic radius= weaker force between outer electron and nucleus = less energy needed to remove electron
how does reactivity with water change as you go down group 2?
increases (Mg lease Ba most)
because outer electron is further from nucleus and more electron shielding, so electrons are lost more easily
write an equation for the reaction with Barium and water?
Ba (s) + 2 H2O (l) —> Ba(OH)2 (aq) + H2 (g)
what is formed when a group 2 metal reactions with water
metal hydroxide X(OH)2
write an equation for the reaction of magnesium and steam?
Mg (s) + H2O (g) —-> MgO (s) + H2(g)
what is the trend in hydroxide solubility down group 2?
Increases down the group
Mg(OH)2 is almost insoluble
Ba(OH)2 creates a strong alkaline solution = very soluble
what is the trend in sulfate solubility down group two?
Decreases down the group
MgSO4 is soluble
BaSO4 is insoluble
what is the trend in melting point down group 2?why?
decreases down the group because…
the sea of delocalised electrons is further from the positive charge of the nucleus = weaker forces of attraction which take less energy to weaken
what is the trend in atomic radius down group 2?
increases as there are more occupied electrons shells down the group
what are the uses of Mg?
Magnesium = used as antacid for stomach acids
Mg(OH)2 + 2HCl —> MgCl2 + 2H2O (Neutralisation reaction)
- used in the extraction of titanium
2Mg(l)+ TiCl4(g) —-> Ti (s) + 2MgCl2(l) (redox)
what are the uses of calcium?
- Ca(OH)2 used in agriculture to increase soil pH
eg. Ca(OH)2 + ACID –> CaSALT + H2O (Neutralisation)
-CaO/CaCO3 used to remove SO2 from flue gases
CaO + SO2 —-> CaSO3 (calcium sulfite)
CaCO3 + SO2 —-> CaSO3 + CO2 bad because carbon dioxide is produced
what are flue gases?
gases produced by power stations which are harmful to the environment
what are the uses of Barium?
BaSo4 used in medicine as a barium meal
Highly insoluble so outlines digestive system for X-Ray viewing to find issues
Ba2+ is toxic but it is fine to use as Barium sulfate as it is insoluble.
How do you test for all group 2 salts?
add Na2CO3 = white ppt for all
