# Can two precipitates form in a precipitation reaction that starts with only two compounds in water? [closed]

Can two precipitates form in a precipitation reaction that starts with only two compounds in water?

• Could you add a little bit of discussion why you think it should or should not be possible? Judging by the phrasing of your question I think you know reactions that form 1 precipitate in such a situation? How much do you know about the thermodynamics of these kind of reactions? – Michiel Jan 28 '14 at 5:30
• I think his question is: can two salts react to precipitate two new salts? – Brian Jan 28 '14 at 8:17
• Actually, I'm confused by the title. Does the OP mean "only two molecules"? This means exactly two molecules. Or does the OP mean "only two compounds", with the amount of each compound open to interpretation? – Ben Norris Jan 28 '14 at 12:06
• I don't see why this should be closed - it seems a perfectly reasonable question to me – user1915639 Mar 27 '14 at 19:05

$$\ce{Ba(OH)2(aq) + MgSO4(aq) -> BaSO4(s) + Mg(OH)2(s)}$$
Above reactants are reasonably soluble in water. From Wikipedia, $\ce{Ba(OH)2}$ has a solubility of 1.67 g / 100 mL at 20 °C and $\ce{MgSO4}$ a solubility of 25.5 g / 100 mL at 20 °C
Yes is the answer to your question provided that reactant two molecules are salts.Two salts can react with eact other and form two new stable salts depending on their $\mathrm{K}_{sp}$ values.