1a
3 marks
Draw dot-and-cross diagrams for the following molecules.
Show outer shell electrons only.
i) Hydrogen cyanide, HCN.
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ii) Carbon dioxide, CO2.
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iii) Boron trifluoride, BF3.
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1b
2 marks
Use your diagrams in (a) to deduce which of the three molecules is most likely to form a coordinate (dative covalent) bond. Explain your answer.
1c
2 marks
i) Draw a dot-and-cross diagram for the product of boron trifluoride and ammonia.
Show outer shell electrons only.
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ii) Explain how the coordinate (dative covalent) bond forms between the boron trifluoride and ammonia molecules.
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