Chapter 8 - Reactivity Trends Flashcards
What are group 2
Alkaline Earth Metals
Trends in reactivity group 2 - state
They become more reactive down the group.
Trends in reactivity group 2 - explain
Their 1st and 2nd ionisation energies reduce down the group. Because as you go down the group, the attraction between the nucleus and the outer electrons decreases. This makes it easier to lose those electrons.
Trends in solubility of metal hydroxides - state and explain
Increases down the group.
As solutions become more alkaline
Experiment to show the trend of solubility in metal hydroxides
- Add a spatula of group 2 hydroxide to a text tube with water
- Shake
- Eventually, a mixture of a saturated solution should be made, with some white solid undissolved at the bottom.
- Measure the pH.
Uses of group 2 elements in agriculture
Added as lime to fields to neutralise the acids and give products of water.
Uses of group 2 elements in medicine
Antacids to treat acid indigestion.
CaCo3 or Mg(OH)2 are used.
Sodium and water
Rapid reaction
It floats and curls up into a ball and floats on the surface of the water due to the hydrogen being formed.
Very exothermic reaction. Hydrogen is formed due to a single displacement reaction.
Tested by doing a squeaky pop test.
Squeaky pop test
A test tube of hydrogen is used to blow out a flame with a “squeaky pop” sound.
Magnesium and water
Ionisation energy increases (from sodium) Reactivity decreases More dense that water so it sinks There's no apparent reaction Very slow reaction without heat
Magnesium and steam
Use a cotton wool with water.
Changes to MgO, which is a white powder.
Magnesium and oxygen
Lightly exothermic
Very bright flame produced.
Sulfur and oxygen
Burns bright blue flame
SO2 is a choking gas.
Sulfur and water
Insoluble in water.
Sodium and steam
Extremely exothermic
What group is the most reactive non-metallic group
Group 7 - Halogens
F2 state
yellow gas
Cl2 state
Green gas
Br2 state
Brown liquid
I2 state
Grey-black solid
At2 state
Never seen