The compound magnesium nitrite is a strong electrolyte. Write the reaction when solid magnesium nitrite is put into water:

Question

Please help I cant with this exersice

he compound magnesium nitrite is a strong electrolyte. Write the reaction when solid magnesium nitrite is put into water:

I have three blank spaces to feel

Answer 1

Hi. I would be happy to answer your question.

Since magnesium nitrite (Mg(NO₂)₂) is a "strong electrolyte" the solid will completely break apart, or "dissociates" in water to produce a cation (the metal, Mg) and an anion (the non-metal portion of the compound, in this case the polyatomic anion, nitrite). Knowing that EACH nitrite anion has a 1^- charge (reference your table of common polyatomic ions) and the magnesium cation always has a 2⁺ charge, we can write this reaction as follows:

Mg(NO₂)_{2 (s)} → Mg²⁺ _(aq) + 2 NO₂^- _(aq)

Pay attention to the fact that for EACH formula unit of magnesium nitrite, TWO nitrite anions are produced. As with every reaction you write, be sure to include phase symbols and verify that it is balanced both by mass and by charge ( the latter is probably a later topic in your course, but helpful here as well).