Q18.
Fluorine and iodine are elements in Group 7 of the Periodic Table.
(a) Explain why iodine has a higher melting point than fluorine.
(2)
(b) (i) Draw the shape of the NHF2 molecule and the shape of the BF3 molecule.
Include any lone pairs of electrons that influence the shape. In each case name the shape.
(4)
(ii) Suggest a value for the F—N—F bond angle in NHF2
(1)
(c) State the strongest type of intermolecular force in a sample of NHF2
(1)
(d) A molecule of NHF2 reacts with a molecule of BF3 as shown in the following equation.
State the type of bond formed between the N atom and the B atom in F2HNBF3.
Explain how this bond is formed.
(2)
(Total 10 marks)