A-LevelChemistryChemical bonding9701/12 · Oct/Nov 2012 · Q31 Mark

Sodium borohydride, NaBH4, and boron trifluoride, BF3, are compounds of boron. What are the shapes around boron in the borohydride ion and in boron trifluoride?

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Aborohydride ion: square planar, boron trifluoride: pyramidal

Bborohydride ion: square planar, boron trifluoride: trigonal planar

Cborohydride ion: tetrahedral, boron trifluoride: pyramidal

Dborohydride ion: tetrahedral, boron trifluoride: trigonal planar

✓ Correct answer

D: borohydride ion: tetrahedral, boron trifluoride: trigonal planar

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Topic: Chemical bonding, A-Level Chemistry (syllabus 9701). Multiple choice, 1 mark.
Source: A-Level Chemistry, Oct/Nov 2012 Paper 1 Variant 2, question 3.

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