DAT Destroyer - Gen Chem - Question on Ksp #315

[Mrhyde]

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For the K constants we never include solids or liquids because they have an activity of 1.
We only include gasses and aq. substances .

So I dont understand how this questions answers can be written correctly , if for the Ksp they all include magnesium . And Magnesium is a metal and thus Mg is a solid and thus would have an activity of 1 and not be included in our Equilibrium Constant Expressions.

So none of the answers should include Magnesium ?

 

[hopefuldentist123]

The reaction gives Mg+2 ions, this is different than Mg (s). When we see Mg+2, it is a charged species. Charged species are ions and are included in Ksp. Magnesium phosphate is an ionic solid that breaks up into magnesium and phosphate ions. It wouldn't break up into solid Mg. Hope this helps!

 

[LuckBloodandSweat]

Mah frend, if you want to destroy the DAT you gotta think ( ͡° ͜ʖ ͡°)