MgCl2 acidic or neutral in water?

manpreet Best Answer 2 years ago

I'm currently taking chemistry 12. On our test we were asked, when given a 0.1 M0.1 M solution of certain compounds whether the resulting solution when added to water would be acidic, basic, or neutral.

At first, I thought the solution would be neutral, because we learnt in class that alkali earth metals and chloride are spectator ions and therefore don't interact with water and pH.

However, I then realized that Mg(OH)2Mg(OH)X2 has low solubility in water, and I assume that adding MgCl2MgClX2, would dissociate and then precipitate Mg(OH)2Mg(OH)X2 from the solution, therefore the resulting solution would be acidic. My final answer was acidic.

The teacher marked my answer wrong, but when questioned could only say that MgMg and ClCl are both spectators, but was unable to give direct contradictory proof against my answer.

I looked elsewhere online and Wikipedia states that anhydrous class="mi" style="margin: 0px; padding: 0px; border: 0