BRAINCAKEGroup 2
Revision notes for Group 2 in Edexcel Chemistry (8CH0). Read the start of any lesson here, then sign in free for the whole lesson, the R.E.C.I.P.E. recall steps and the quiz.
- Group 2 ElementsGroup 2 metals are called the alkaline earth metals.
- Trend In Ionisation EnergyGroup 2 first ionisation energies decrease down the group as the elements get more reactive.
- Trend in ReactivityThe reactivity of redox reactions increases down group 2 because the atoms lose their two outer electrons more easily to form +2 ions.
- Reactions with OxygenBarium is often stored under oil to prevent it reacting with water vapour or oxygen in the air.
- Reactions with ChlorineGroup 2 elements combine with chlorine when heated in the gas.
- Reactions with WaterMagnesium reacts only very slowly with cold water.
- Magnesium and SteamMagnesium reacts with steam to form magnesium oxide: Mg (s) + H2O (g) → MgO (s) + H2 (g) The hydrogen is burned as it forms for safety as it is…
- Reactions of Oxides with WaterGroup 2 oxides are basic oxides and can react with water to form alkalis which are colourless solutions.
- Trends in Solubility of the HydroxidesMagnesium hydroxide has very low solubility in water.
- Uses of the HydroxidesMilk of Magnesia Milk of Magnesia is a saturated solution of magnesium hydroxide mixed with solid magnesium hydroxide.
- Reactions of the Oxides and Hydroxides with AcidsThe white solids react to form colourless solutions.
- Trend in Solubility of SulfatesThe solubility of sulfates decreases down the group. • Magnesium sulfate is soluble • Calcium sulfate is slightly soluble • Strontium sulfate and…
- Thermal Stability of NitratesThermal Stability of Nitrates When heated all group 1 and group 2 nitrates decompose to nitrites or oxides and give off nitrogen dioxide (brown…
- Thermal Stability of CarbonatesWhen group 2 carbonates are heated they decompose into the oxides and carbon dioxide with increasing difficulty down the group.
- Flame TestsHow to do a Flame Test •Wear safety glasses and a labcoat and carry out in a fume cupboard. •Dip a clean nichrome metal wire into concentrated…
- Test for Ammonium IonsTest for Ammonium Ions Ammonium ions do not give a colour in a flame test.