Group 17 Flashcards
What is significant about the elements in group 17?
They are the first group to contain all non-metals.
Why does F2 have unusually weak bonds?
It is small so there is lots of lone pair-lone pair repulsion, making the bond weaker than anticipated.
How does bond strength of the diatomic covalent molecules change down the group?
They increase from F2 to Cl2 and then decrease down the group.
What is the most common oxidation state?
-1.
Why is the boiling point of HF low?
It has unidirectional H-bonding compared to H2O which has a 2D H bonding network. The H bonding is retained even when heating to 60 degrees. Not all of the hydrogen bonds need to be broken for the compound to boil, hence the low boiling point.
Why is HF a weaker acid compared to those going down the group?
HF is a strong bond and there is ion pair formation betwen H3O+and F-.
What oxidation state does F adopt?
0 or -1.
What oxidation states can the halogens other than F adopt?
-1, 0, +1, +3, +5 and +7.
What are the properties of the interhalogens?
The biggest atom is always the central one and they are all highly reactive.
What does exergonic mean?
The formation enthalpy is less than zero.
What is PTFE?
Telfon - polytetrafluroethylene.
