solubility question

[ippie]

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The reaction of AgNO3 and Na2SO4 in water goes to completion because

a. silver sulfate quickly precipitates
b. water is a strong electrolyte
c. it is a neutralization reaction
d a volatile product is formed
e. sodium sulfate is a very strong acid

This question is in #49 of Kaplan full lenth test 1.
The answer is A.
Do you think Ag2SO4 precipitates?
SO4(2-) is soluble with exception of Ca(2+), Sr(2+), Ba(2+) and Pb(2+).
Can anybody explain? I think this problem is wrong itself.

 

[dat_student]

The reaction of AgNO3 and Na2SO4 in water goes to completion because

a. silver sulfate quickly precipitates
b. water is a strong electrolyte
c. it is a neutralization reaction
d a volatile product is formed
e. sodium sulfate is a very strong acid

This question is in #49 of Kaplan full lenth test 1.
The answer is A.
Do you think Ag2SO4 precipitates?
SO4(2-) is soluble with exception of Ca(2+), Sr(2+), Ba(2+) and Pb(2+).
Can anybody explain? I think this problem is wrong itself.

Read the rules about Ag,..it's been a while...as far as I remember Ag is insoluble unless coupled w/ group I or NO3. Plus, you have to follow the order of the rules & priorities 🙂

 

[ippie]

In Kaplan Review Book p914, there's no rule about Ag.
Ag has rule too?

 

[dat_student]

In Kaplan Review Book p914, there's no rule about Ag.
Ag has rule too?

Yes, it does. I came up with a set of rules for myself after reading Kaplan, Princeton Review, EK, AP. It's a long list. When is your test? I don't feel like typing the whole thing now. If not urgent I'll post it in the next few days

 

[ippie]

Thank you so much~
My test is this coming thursday (Aug. 3). Please, post it. Thank you! 😍

 

[allstardentist]

yeah.. Ag got some rules, they are all insoluble except its nitrates, perchlorates, and acetates. therefore, Ag2SO4 precipitates

 

[allstardentist]

thats according to princeton review mcat book

 

[dat_student]

thats according to princeton review mcat book

yes pg. 396 🙂 good old times. I used to teach some of Kaplan's MCAT classes 😉 I kinda like Princeton Review books a little better.

 

[dat_student]

Thank you so much~
My test is this coming thursday (Aug. 3). Please, post it. Thank you! 😍

What's your email address? It'd be easier to send you a snap shot.

 

[allstardentist]

agree, if anyone can get a hand on the princeton review mcat book, they should use it. def better than kaplan at explaining stuff.

 

[ippie]

[email protected]
Thank you~

 

[dat_student]

...

sent >> check both your in-box and bulk folders. I sent a large file. Just follow the 8 rules. #4 is ...except sulfates of pb2+ & ca2+ + Ba2+ forms insoluble salts w/ SO42- & PO4 3-. That is from one of my AP books (pg. 236). Also remember #1 has the highest priority. GOOD LUCK 🙂

 

[Notoriousjae]

I dont think A is the right answer and i do agree that the problem in itself is wrong
all sulfate salts are soluble with the exception of barium, strontium, calcium, lead and mercury. It does not mention silver.
all chloride, bromide and iodide salts are soluble except for silver, mercury, and lead.
If it was AgCl, AgBr, or AgI then it would be insoluble but it doesnt mention Ag as an exception for sulfate salts. I referenced this with the kaplan blue book and the zumdahl textbook.

 

[allstardentist]

not all sulfates are soluble, for ex. AgSO4

 

[Notoriousjae]

not all sulfates are soluble, for ex. AgSO4

According to the rules in the books that i have it doesnt mention Ag as an exception but i'll keep that in mind in case it shows up on the DAT

 

[GRAD]

According to the rules in the books that i have it doesnt mention Ag as an exception but i'll keep that in mind in case it shows up on the DAT

Its not in the Kaplan book and that sucks cause who know what else isnt in there, but A is correct

Most sulfate salts are soluble. Important exceptions to this rule include BaSO4, PbSO4, Ag2SO4, and CaSO4.