Question

Write the net ionic equation for this reaction occurring in water: ammonium fluoride and magnesium chloride are mixed to form magnesium fluoride and ammonium chloride. 1. no reaction occurs. 2. 2 nh+ 4 + 2 cl− → 2 nh4cl 3. 2 f− + mg2+ → mgf2 4. 2 nh4f + 2 cl− → 2 f− + 2 nh4cl 5. 2 f− + mgcl2 → mgf2 + 2 cl−

Answer 1

Correct answer: 3. $Mg^{2+}(aq) + 2 F^{-}(aq) --> MgF_{2}(s)$

The given chemical reaction is between ammonium fluoride and magnesium chloride to form magnesium fluoride and ammonium chloride.

The balanced chemical equation representing the reaction will be,

$2NH_{4}F (aq) + MgCl_{2}(aq) -->MgF_{2} (s) + 2NH_{4}Cl (aq)$

The complete ionic equation for the reaction: All the compounds soluble in water (aqueous) will split into ions, $MgF_{2}$ will not split into ions as it is insoluble in water.

$2 NH_{4}^{+}(aq) + 2 F^{-}(aq) + Mg^{2+}(aq) + 2 Cl^{-}(aq) --> MgF_{2}(s) + 2 NH_{4}^{+}(aq) + 2 Cl^{-}(aq)$

The net ionic equation will be:

$Mg^{2+}(aq) + 2 F^{-}(aq) --> MgF_{2}(s)$

Here the spectator ions are $NH_{4}^{+} and Cl^{-}$