Q20.
Fluorine forms many compounds that contain covalent bonds.
(a) (i) State the meaning of the term covalent bond.
(1)
(ii) Write an equation to show the formation of one molecule of ClF3 from chlorine and fluorine molecules.
(1)
(b) Draw the shape of a dichlorodifluoromethane molecule (CCl2F2) and the shape of a chlorine trifluoride molecule (ClF3). Include any lone pairs of electrons that influence the shape.
(2)
(c) Suggest the strongest type of intermolecular force between CCl2F2 molecules.
(1)
(d) BF3 is a covalent molecule that reacts with an F– ion to form a BF4– ion.
(i) Name the type of bond formed when a molecule of BF3 reacts with an F– ion. Explain how this bond is formed.
(3)
(ii) State the bond angle in the BF4– ion
(1)
(e) An ultrasound imaging agent has the formula C4F10
It can be made by the reaction of butane and fluorine as shown in the following equation.
C4H10 + 10F2 → C4F10 + 10HF
Calculate the percentage atom economy for the formation of C4F10 in this reaction.
Give your answer to three significant figures.
(2)
(Total 11 marks)