Chemistry Question

Question

Complete and balance the precipitation reactions. Include physical states. Refer to the solubility rules as necessary. precipitation reaction: Ba ( NO 3 ) 2 ( aq ) + CuSO 4 ( aq ) ⟶ Ba ( NO 3 ) 2 ( aq ) + CuSO 4 ( aq ) ⟶ precipitation reaction: K 3 PO 4 ( aq ) + MgCl 2 ( aq ) ⟶ K 3 PO 4 ( aq ) + MgCl 2 ( aq ) ⟶

Answer 1

Hi Anna M.,

This exercise is asking you to use your knowledge of what substances have low solubility. That would be, salts of any cation of charge >+1 with any anion of charge >-1 (well, you know what I mean, in a mathematical sense it's charge <-1, but that's not how a chemist thinks!). So, any time you have those 2 types of things in solution together, they're liable to precipitate out in the stoichiometrically appropriate salt. I say that, because what exact ion of phosphate will be pulled down, for example, may depend upon the exact pH at the point of reaction.

So, you know your cation and anion charges? Make or find a table of them, and the rest is easy! (Making is better than finding, since it gives you an additional chance to memorize some ion formulas and charges.)

-- Cheers, -- Mr. d.