Calculate the lattice energy of CSCI (S) using the following thermodynamic data (all data is in kJ/mol). Note that the data given has been perturbed, so looking up the answer is probably not a good idea. Cs (s) Cs (g) AHsublimation 57 kJ/mol Ionization energy = 356 kJ/mol Cl- Cl (g) Bond energy = 223 kJ/mol Cl (9) Electron affinity -369 kJ/mol CsCl (s) AH°-463 kJ/mol kl/mol

The table below shows some physical properties of halogenatedliquids.   Which of the following statements best explains these data?(a) The larger the dipole moment, the stronger the intermolecularforces, and therefore the boiling point is lowest for themolecule with the largest dipole moment. (b) The dispersionforces increase from F to Cl to Br; since the boiling point alsoincreases in this order, the dispersion forces must make a fargreater contribution to intermolecular interactions thandipole-dipole interactions. (c) The trend in electronegativityis F > Cl > Br; therefore, the most ionic compound (CH2F2)has the lowest boiling point, and the most covalent compound(CH2Br2) has the highest boiling point. (d) Boiling point increaseswith molecular weight for these nonpolar compounds.

Structure and Bonding Cyanamide, NH2CN, has a melting point of 45 °C. (a) Draw a dot-and-cross diagram to illustrate the electron arrangement in NH2CN. (b) Name the predominant intermolecular interaction that could account for the melting point of cyanamide, and illustrate your answer with a diagram. (a) The melting point of NaCl was found to be 801 °C. Suggest, with reasons, whether the melting point of MgO will be higher or lower than that of NaCl. 3 (Refer to Section 1.2.2, pg 4 of Topic 3 Lecture Notes to revise how to compare ionic bond strength) (b) The boiling points of ammonia, carbon monoxide and carbon dioxide are given in the table below: gas formula Mr b.p. /°C ammonia NH3 17 -33 carbon monoxide CO 28 -192 carbon dioxide CO2 44 -78 With reference to their structure and bonding, account for their boiling points. (Refer to Section 5, pg 22 of Topic 3 Lecture Notes to revise how to identify the type of IMF)

Regarding the stability of the permanganate solution: describe the reactions that occur when it decomposes. Indicate which factors catalyze its decomposition and indicate how they can be controlled.