Structure, Bonding and Organic

    1. State whether the compounds formed by each pair of elements given in (a) and (b) are likely to be:  (i) ionic or covalent, giving your reasoning  (ii) give the chemical formula  (iii) name of the compound      (a) Mg and N  (b) N and F  [2 x 3 marks] 2. Draw the dot / cross (Lewis) diagrams for the two compounds formed in Question 1, showing only electrons in the outermost electronic shell (valence shell).  [2  2 marks]3. For the following pairs of elements or compounds, (i) State which member of the pair will have the highest boiling temperature.  (ii) Identify what particles are actually separated by the vaporisation process of each of those elements or compounds and hence explain your answer to part (i) in each case. (iii) List all the interactions that were holding these particles together before vaporisation.(a) K and Mg                                                                                   (b) HF and NaF (c) CCl4 and CHCl3  [12 marks] 4. Consider the following set of molecules: CH3Br C2H4 C2H3F H2O HCN NH3 BCl3 CCl4 CO2 H2O2 (a) List all the molecules in that set that have a linear shape, and justify your answer. (b) List all the non-polar molecules in that set, and give their shape.         [8 marks]5.  (a)  Draw the skeletal structure for (i) 2-fluoropropanal  (b) Name the molecules below using the IUPAC nomenclature(i) CH3CH2COCH2CH3 (ii) CH2FCHBrCH2COOH                                                         [2 marks] 6. Give the structural formulae and names of all the positional isomers of C4H8F2                [6 marks]7. CH3CH2CBr(OH)CH3 exists as two optical isomers.  (a) Name the above molecule using the IUPAC nomenclature  (b) Draw two 3-dimensional diagrams showing clearly the difference between the                 two optical isomers [3 marks] 8. Geraniol is a component of essential oils that is used in perfumery and flavoring. It is an oily liquid at room temperature and pressure. The skeletal formula of geraniol is given below:       Geraniol  (a) Structure and isomers of geraniol.(i) Draw the displayed formula of geraniol   [1 mark](ii) How many geometric isomers of Geraniol are there? Justify your answer, and draw them. [4 marks] (b)  Name all the functional groups present in geraniol. .     [1 mark]      (c) A drop of geraniol is added to a solution of 2,4-DNPH (Brady’s reagent).     What, if anything, is observed? Justify your answer.   [2 marks]     (d)  As part of an investigation of its structure, a sample of geraniol is treated with a little                  acidified potassium dichromate, always ensuring that geraniol is in excess. A mixture               of the products formed is extracted by steam distillation, and a few drops of that               mixture added to a solution of 2,4-DNPH.  The addition of 2,4-DNP leads to the               formation of a bright yellow precipitate.                  (i) What does the formation of a yellow precipitate upon reacting with 2,4-DNPH                             indicate? [1 mark]                 (ii)  Why was the geraniol  in excess during treatment with acidified potassium                        dichromate? [2 marks]      (iii)  Which further test would you conduct to determine whether geraniol is a                                               primary or secondary alcohol? Explain your reasoning. [2 marks](e) A sample of 2,6-dimethylocta-2,6-diene is treated with an excess of HBr. Give the structural formula of all the products of this reaction. [4 marks]