Topic 4 Inorganic Chemistry Flashcards
What is a common name given to group 2 metals?
Alkaline earth metals
What is the most reactive metal of group 2?
Barium
List 3 physical properties of group 2 metals
● High melting and boiling points
● Low density metals
● Form colourless (white) compounds
The highest energy electrons of group 2 metals are in which subshell?
S subshell
Does reactivity increase or decrease down group 2? Why?
● Increases
● Electrons are lost more easily because larger
atomic radius and more shielding.
What happens to the first ionisation energy as you go down group 2? Why?
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
What type of reaction is the reaction between group 2 elements
and oxygen?
Redox reaction
Write an equation for the reaction of calcium and oxygen
2Ca (s) + O 2 (g) → 2CaO (s)
What is the product when group 2 elements react with water?
Hydroxide and hydrogen gas
Which group 2 element doesn’t react with water?
Beryllium
Which group 2 element reacts very slowly with water?
Magnesium
What type of reaction is the reaction between group 2 metal and
water?
Redox reaction
Write an equation for the reaction of Barium and water
Ba (s) + 2H 2 O (l) → Ba(OH)₂ (aq) + H₂ (g)
What is oxidised and what is reduced in a reaction between group
2 metal and water?
Metal → oxidised
One hydrogen atom from each water → reduced
What are the products when group 2 oxide reacts with dilute acid?
Salt and water
Write an equation for the reaction of calcium and hydrochloric acid
CaO (s) + 2HCl (aq) → CaCl 2 (s) + H₂O (l)
What is formed when group 2 oxides react with water?
Metal hydroxide
Write an equation for the reaction between a group 2 oxide and
water
MO (s) + H 2 O (l) → M(OH) 2 (aq)
Which group 2 metal oxide is insoluble in water?
Beryllium oxide
Write an equation for the reaction between Mg(OH) 2 and nitric acid
2HNO 3 (aq) + Mg(OH) 2 (aq) –> Mg(NO 3 ) 2 (aq) + 2H2O (l)
What is the trend in hydroxide solubility down group 2?
Increases down the group
Ca(OH)₂ is slightly soluble
Ba(OH)₂ creates a strong alkaline solution
What is the trend in sulphate solubility down group 2?
Group 2 sulphates become less soluble down the group with BaSO4 being the least soluble
Explain the reasons for the trend of thermal stability in group 1 carbonates
Group 1 carbonates do not decompose except for lithium. This is because they don’t have a big enough charge density to polarise the carbonate ion as they only form 1+ ions. However Lithium ion is small enough to have a polarising effect so therefore lithium carbonate can decompose.
Explain the reasons for the trend of thermal stability in group 2 carbonates
Group 2 carbonates are more thermally stable as you go down the group this is because the cations get bigger so therefore have less of a polarising effect distorting the carbonate ion less. As C-O bond is not weakened as much it harder to break down
Explain the reasons for the trend of thermal stability in group 1 nitrates
Group 1 nitrate do not decompose with the exception of Lithium nitrate. Lithium ion is smaller enough to charge polarisation of the nitrate anion and thus weakening
the N-O bond.
Explain the reasons for the trend of thermal stability in group 2 nitrates
The ease of thermal decomposition decreases down group 2 and this is because down the group the ions get larger and therefore has less charge density = less polarisation of nitrate anion and less weakening of the N―O bond
What is the flame colour of Lithium
Red
What is the flame colour of Sodium
Yellow
What is the flame colour of Potassium
Lilac
What is the flame colour of Magnesium
none, cuz the photons emitted has a frequency outside the visible light spectrum
What is the flame colour of Calcium
Brick red
What is the flame colour of Strontium
Red
What is the flame colour of Barium
Apple green