Homework Help: Forming precipitates

What is the charge on the SO4 diatomic ion? What combines with SO4 to turn it into an insoluble compound?

From what I'm reading here, this looks like a problem designed to test your knowledge of the solubility rules. As is the case with many solubility rules problems, this one looks like it is also testing you on your knowledge of ionic charges -- this is just something you need to know how to do, and sometimes the only way of knowing the charge of something (such as the diatomic ions) is through memorization.

 

Here's ahttp://www.csudh.edu/oliver/chemdata/solrules.htm" [Broken], but they really should be in your text book.

 

this is chemistry that you learn in lower classes! have you just got into high school?!

 

If he's in high school chemistry, then these would be the types of problems that he'd work. Is there something wrong with that?

 

awww i'm sorry.... i didn't mean it like that....
sry again

 

Part of your problem is that you are writing molecules rather than ions for the ionic equation. Try this:

2H^+1 + SO4^-2 + Ba^+2 + 2Cl^-1

Then use the solubility rules mentioned above and find out which ions form precipitates and which remain in solution after the reaction is complete. If you need any more help, just let me know.

(I could repost the equation with LaTeX if this is kind of unreadable--just let me know.)

 

solubility rules you have to learn:

all nitrates (NO3-) are soluble
all chlorides (Cl-) are soluble except lead chloride (PbCl2) and silver chloride (AgCl2)
all sulphates ((SO4)2-)are soluble except lead sulphate (PbSO4), barium sulphate (BaSO4) and Calcium sulphate (CaSO4) which is sparingly soluble.
all alkali metal salts are soluble (sodium (Na+), potassium (K+),.... salts)
all ammonium (NH4+) salts are soluble
all carbonates ((CO3)2-) are INSOLUBLE except alkali metal carbonates (sodium carbonate Na2CO3,....) and ammonium carbonate ((NH4)2CO3)

this is what you need in HS ;)

 

when dealing with ionic compounds you have to satisfy the charge. an ionic salt will consist of a positively charged ion (cation) combined with a negatively charged ion (anion). the magnitude of the charges of both ions should be equal.

for example, with magnesium sulphate. magnesium ion is Mg2+ and sulphate ion is (SO4)2-
the salt is then MgSO4 since the magnitude of charges on both ion is 2.

but with sodium sulphate, sodium ion is Na+ and the sulphate ion is (SO4)2-
the salt is then Na2SO4. there are 2 sodium ions so that in total the positive charge is +2. this balances with the -2 charge on the sulphate.