(a) Describe and explain the trend in the boiling points of the elements down group VII from Fluorine to Iodine. All of the halogens exist as diatomic molecules (F2, Cl2 and I2) the intermolecular attractions between the molecules hold them together. The larger the molecule (as it moves down the halogen group) the bigger the intermolecular forces are between electrons because with more rings the distance between each electron is larger. The larger elements such as Bromine and Iodine are larger molecules with a larger amount of intermolecular force between each electron. This increase in intermolecular attraction means that the required heat energy to reach the boiling point increases. Fluorine has a significantly lower boiling point than the rest of the halides because it has a set of electrons that produces repulsion between them. This weakens the bond. Chlorine has a boiling point of -34.6°C because its covalent bond is stronger than fluorine’s and so on until Iodine which has a boiling point of 184.0°C because it has many more energy levels which requires more heat energy. As the intermolecular and the amount of energy shells increase so does the boiling point (increases down the group)
(b) Describe what you would observe when aqueous Silver nitrate is added to separate aqueous solutions of Sodium chloride and sodium Bromide
When the solution of sodium chloride is added to the aqueous solution of silver nitrate it would be displaced by the sodium chloride to form a silver chloride and sodium nitrate. This would happen because the chloride is a more reactive element and displaces the weaker element, which is the silver. The silver chloride is insoluble and this would form a white precipitate.
AgNO3 (aq) + NaCl (aq) NaNO3 (aq) + AgCl(s)
Ag+ (aq) + Cl- (aq) AgCl (s)
When you add the aqueous solution of silver bromide to the silver nitrate it will be displaced by the sodium bromide, as the bromide is the more...