JEE Main2018ChemistryEnvironmental ChemistryActual
The recommended concentration of fluoride ion in drinking water is up to 1 ppm as fluoride ion is required to make teeth enamel harder by converting 3 Ca 3 PO 4 2 . Ca OH 2 to:
Options
- A3 Ca OH 2 . CaF 2
- BCaF 2
- C3 CaF 2 . Ca OH 2
- D3 Ca 3 PO 4 2 . CaF 2
Correct answer
D. 3 Ca 3 PO 4 2 . CaF 2
Step-by-step solution
The recommended concentration of fluoride ion in drinking water is up to 1   ppm   as fluoride ion is required to make teeth enamel harder by converting [   3   Ca 3 ( PO 4 ) 2 . Ca ( OH ) 2   ] to [   3   Ca 3 ( PO 4 ) 2 . CaF 2   ] . [   3   Ca 3 ( PO 4 ) 2 . Ca ( OH ) 2   ] + 2   F -   →   [   3   Ca 3 ( PO 4 ) 2 . CaF 2   ]