Group 2 Metals Flashcards
(14 cards)
Describe the first ionisation down group 2
- the atomic radius gets bigger down the group
- more shielding down the group
- attraction between nucleus and outer shell electron decreasing down the group
- therefore lower ionisation energy down the group
Describe melting point down group 2
- lower melting points down the group as weaker metallic bonding
- weaker metallic bonding as atoms (ions) get bigger
- change in trend after Mg is due to change in way atoms (ions) pack together
(Pack together in a closer arrangement)
What happens to the ions when an ionic substance dissolves?
- when an ionic substance dissolves
- the ions separate and mix in with the water
e.g. NacCl and NaCl
What happens when you mix solutions of two ionic compounds?
- mix solutions of two ionic compounds
- the just mix
e.g. Mg(NO3)2 and H2SO4
What happens when you mix solutions of two ionic compounds?
- mix solutions of two ionic compounds
- or a precipitate may form
(If given a combination of ions that is insoluble)
e.g. Ba2+ (aq) + SO4 2- (aq) —-> BaSO4 (s)
Test for sulfate ions
- add dilute hydrochloric acid followed by barium chloride solution
- a white precipitate formed of barium sulfate
(Means the original compound was a sulfate)
Carbonates effervescence and the equation
- CO2 is formed when an acid and carbonate reacts
- To test for CO2, it turns limewater milky (a precipitate formed)
XCO3 + HCl —-> XCl + CO2 + H2O
Carbonate + acid —-> salt + carbon dioxide + water
Extraction of titanium
- Mg is used to extract Ti from the one rutile (TiO2)
- Mg is used to extract Titanium from Titanium chloride through a displacement reaction
TiCl4 (l) + 2Mg (s) —-> 2MgCl2 (s) + Ti (s)
Flu gas removal:
- CaO in flu gas desulfurisation
CaO + SO2 —-> CaSO3
- reacting Calcium Oxide with sulfur dioxide to remove pollutants being released
CaO + 2H2O + SO2 —-> CaSO3 + 2 H2O
State barium sulphate’s formula, what it’s used for and why?
Barium sulphate:
Formula: BaSO4
Used for:
Barium meal
Imaging of the body organs
Why: insoluble
State magnesium’s formula, what it’s used for and why?
Magnesium:
Formula:
TiO2 + 2C + Cl2 —-> TiCl4 + 2CO
TiCl4 + 2Mg —-> Ti + 2 MgCl2
Used for:
Mg used to extract Ti from the rutile (TiO2)
Why: more reactive than Ti
State Magnesium hydroxide’s formula, what it’s used for and why?
Magnesium Hydroxide:
Formula: Mg (OH)2
Used for:
Treating
Indigestion
Milk of magnesia
Why:
as its a base so will neutralise stomach acid
Insoluble
State calcium hydroxide’s formula, what it’s used for and why?
Calcium Hydroxide:
Formula: Ca (OH) 2
Used for: slaked lime
Why: neutralise soil pH
State calcium carbonate’s formula, what it’s used for and why?
Calcium Carbonate:
Formula: CaCO3
Used for:
Desulfurisation
CaO + SO2 —-> CaSO3
