Question

Which net ionic equation would match this description of a chemical reaction: When a

Answer 1

Answer:

$3Mg^{2+}(aq.)+2PO_{4}^{3-}(aq.)\rightarrow Mg_{3}(PO_{4})_{2}(s)$

Explanation:

$Mg(NO_{3})_{2}$, $Na_{3}PO_{4}$ are strong electrolytes. Hence they are fully ionized in aqueous solution.

$Mg_{3}(PO_{4})_{2}$ is a sparingly soluble salt. Hence it remains undissociated in aqueous solution.

So, total ionic equation:

$3Mg^{2+}(aq.)+6NO_{3}^{-}(aq.)+6Na^{+}(aq.)+2PO_{4}^{3-}(aq.)\rightarrow Mg_{3}(PO_{4})_{2}(s)+6Na^{+}(aq.)+6NO_{3}^{-}(aq.)$

Net ionic equation is written by omitting spectator ions from total ionic equation.

Here, $Na^{+}$ and $NO_{3}^{-}$ ions are spectator ions as they remain present on both side of total ionic equation.

So, net ionic equation:

$3Mg^{2+}(aq.)+2PO_{4}^{3-}(aq.)\rightarrow Mg_{3}(PO_{4})_{2}(s)$

So, option (d) is correct.