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Compounds of group 1 and 2. www.thescienceteacher.co.uk. Ionisation energy . Describe the trend in I.E as you descend group 2 Explai n this trend in I.E. Key terms : valence electron; distance from nucleus; atomic radius, shielding Predict the trend in reactivity of Grp2. Group 2.
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Compounds of group 1 and 2 www.thescienceteacher.co.uk
Ionisation energy Describe the trend in I.E as you descend group 2 Explain this trend in I.E. Key terms: valence electron; distance from nucleus; atomic radius, shielding Predict the trend in reactivity of Grp2 Group 2 Solublitiy SO42- OH1- As you descend group 2 the sulphates become ________ soluble and the hydroxides become ________ soluble If the hydroxide is soluble we get an alkaline solution CaO (s) + H2O(l) Ca(OH)2(aq) hydroxides get higher! 2OH- Ca2+
Charge denisty Nitrate Thermal Stability World Ranking Grp1NO3 ____ + ____ Grp2(NO3)2 ____ + ______ + ____ Put these nitrates in order of thermal stability: NaNO3, Mg(NO3)2, KNO3 and Ca(NO3)2 Most stable: 1. 2. 3. Least stable 4. Carbonate Thermal Stability World Ranking XCO3 ______ + ______ Put these carbonates in order of thermal stability: CaCO3, Na2CO3, K2CO3 and MgCO3 Most stable: 1. 2. 3. Least stable 4. Polarisation of anions Ionic compounds decompose at different temperatures. This is because lare anions can become polarised by small highly charged cations. Describe, in terms of charge and size of the cation why: NaNO3 is more stable than Mg(NO3)2 Group 2 carbonates become more stable as you descend the group Charge denisty How would you carrry out an experiment to compare the stability of group 2 nitrates? How would you carry out an experiment to compare the stability of group 2 carbonates? Blue = atomic radius; grey = ionic radius
MgCO3, MgO, BaCO3 You are working in a space station and have the four compounds above. You need to find the compound that is best suited to the following tasks. You only have enough of each compound to use it once. Chose carfefully and justify your choices • You need an indigestion tablet to give to a crew member with serious heart burn. • You need to repair the kiln lining wihtin the space station. This lining must be able to withstand intense heat • You need a source of carbon dioxide to refill the carbon dioxide fire extinguisers