1. Periodic Table Properties and reactions of group 2 –Ionisation energy –Flame colours (includes group 1) –Reactions with oxygen, water and chlorine –Solubility of hydroxides and sulfates –Thermal stability of carbonates and nitrates –Titrations – done in unit 1 (coursework) Inorganic chemistry of group 7 –Physical properties –Oxidation reactions –Disproportionations –Iodine/thiosulfate titrations –Reactions of halides with: solids with conc sulfuric acid; solutions with silver nitrate/dilute nitric acid Identification tests (coursework)

2. Homework AS LabSkills – linked to in moodleAS LabSkills –Work through ‘Techniques’ Lab calculations Tests and observations –Work through ‘Experiments’ Acid-base titration Redox titration Identification of unknown Textbook –Read chapter 11 pages 147-155 –Carry out the test yourself tasks and activity on p 154 –Read chapter 12 p 164-173 –Carry out the test yourself tasks and activity on page 172

3. Learning objective: WALT: Revising trend in ionisation energies of group 2 Using flame tests to identify group 1&2 cations in compounds WILF: Summary of flame colours and why we get them 10/06/2016 Explain the following trend: M (g)  M + (g) + e - M + (g)  M 2+ (g) + e - Be9001800 Mg7401500 Ca5901100 Sr5501100 Ba5001000

4. Ionisation energies M (g)  M + (g) + e - 1 st (& 2 nd ) ionisation energies decrease down group: outer electrons further from nucleus more shielding from full shells BUT (!) more protons in nucleus [first two outweigh third]

5. Flame colours Set up a Bunsen with a blue flame Dip a nichrome loop in concentrated hydrochloric acid Place in flame Repeat until flame remains blue Dip loop in acid and then a small sample of group 1 or 2 chloride Record the flame colour If the yellow is masking another colour look through a blue filter

6. Flame colours lithium sodium potassium calcium strontium barium Emission spectra:

7. Set up two test tubes containing about 1 cm 3 magnesium chloride Repeat for the other group 2 chlorides To the first tube of each chloride add an equal volume of sodium sulfate To the second tube add an equal volume of barium hydroxide Solubility of group 2 compounds

8. Hydroxides increasingly soluble down group M 2+ (aq) + 2 OH - (aq)  M(OH) 2 (s) Sulphates decreasingly soluble down group M 2+ (aq) + SO 4 2- (aq)  MSO 4 (s) REMEMBER The test for SO 4 2- is add Ba 2+ to make… thick white precipitate i.e. BaSO 4 is completely INSOLUBLE