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Identify the incorrect pair from the following.

1. Cryolite – Na 3 AlF 6
2. Fluoroapatite – 3Ca 3 (PO 4 ) 2 ⋅ CaF 2
3. Fluorspar – BF 3
4. Carnallite – KCl ⋅ MgCl 2 ⋅ 6H 2 O

Correct answer: Fluorspar – BF 3

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