Group 2 elements and their compounds Flashcards
What is the general eqn when one is heated in pure oxygen?
2M + O2 → 2MO2
What are the colour of each of their flames: Mg, Ca, Sr and Ba
Mg - Bright white light
Ca - Brick red
Sr - Red
Ba - Green
What is the apparatus for reacting a group 2 metal with water?
In book
What is the eqn for reacting a group 2 metal with water
M + 2H20 → M(OH)2 + H2
What are the observations for Mg, Ca, Sr and Ba
Mg - few bubbles metal dulls
Ca, Sr, Ba - Heat released, bubbles produced and metal disappears
What is the general eqn for the group 2 elements and steam? w/ state symbols
M (s) + H20 (g) → MO (s) + H2 (g)
Draw the apparatus for reacting a group 2 metal w steam
in book
What are the observations?
Mg - Burns with a bright white light, white powder produced
Ca, Sr, Ba - Rd, Red, Green and forms white solid
Reaction of group 2 metals and dilute mineral acids e.g. H2SO4 and HCl
M + 2HCl → MCl2 + H2
M +H2SO4 → MSO4 + H2
What are the observations?
Heat released, bubbles produced, metal disappears, colourless solution formed
Reaction of group 2 metal oxides and water?
And observations
MO + H20 → M(OH)2
Heat released, colourless solution formed
Reaction of group 2 metal oxides with dilute mineral acids e.g. HCl AND observations
MO + HCl → MCl2 + H2O
Heat released, solid disappears, colourless solution formed
What are some uses of group 2 metal compounds?
MgO - ingestion remedies reacts with excess HCl
CaCO3 - neutralises acid on the teeth
Thermal stability of group 2 CARBONATES and explanation
Thermal stability increases from MgCO3 to BaCO3
- The size of the metal cation increases down the group
- The charge density of the cation decreases
- The cation is less able to polarise and destabilise the carbonate ion
Thermal stability of group 2 HYDROXIDES
Thermal stability increases from MgCO3 to BaCO3
- The size of the cation increases down the group
- The charge density of the cation decreases
- The cation is less able to polarise and destabilise the carbonate ion
