• Livestream AMA: Join SDN as we welcome Dr. John Ligon, a Pediatric Oncologist with the National Cancer Institute on May 11th at 8:00 PM Eastern. Register now!

peyman2002

10+ Year Member
Sep 5, 2007
177
0
Status (Visible)
  1. Pre-Dental
I need for somebody to explain this:
we have Na2(So4) saturated solution and we add base according to the answer the following occurs:

Increasing the solution’s basicity will disrupt the equilibrium between sulfate and its conjugate acid leading to an increase in sulfate ion concentration: HSO4- + OH- -> SO42- + H2O. An increase in sulfate ion concentration will cause precipitation of sodium sulfate via the common ion effect.

ok. Na2So4 is soluble and if we add OH should NaOH form which would result in disolving more of Na2So4?
 

Danny289

Member
10+ Year Member
Dec 2, 2006
1,523
4
Status (Visible)
  1. Pre-Dental
I need for somebody to explain this:
we have Na2(So4) saturated solution and we add base according to the answer the following occurs:

Increasing the solution’s basicity will disrupt the equilibrium between sulfate and its conjugate acid leading to an increase in sulfate ion concentration: HSO4- + OH- -> SO42- + H2O. An increase in sulfate ion concentration will cause precipitation of sodium sulfate via the common ion effect.

ok. Na2So4 is soluble and if we add OH should NaOH form which would result in disolving more of Na2So4?

base is not in saturated in our soluion, we won't have reverse for NaOH.
 

Danny289

Member
10+ Year Member
Dec 2, 2006
1,523
4
Status (Visible)
  1. Pre-Dental
danny ghorboonet, bazam nageraftam!
could u explain more plz?

Okay Paymanjan lets try together we have these two equations
1) Na2SO4 <===>2 Na+ +SO42-
2) SO4-2 + H20 <===> HSO4- + OH-

Now adding base, means adding OH-,
In your second equation you are increasing OH- then your equilibrium will shifts to the left that means more SO4-2.
Just remember we can not write anything like Na+ +H2O <===> NaOH + H+
Even you can approach another way but maybe it is a little more conceptual. Lets try this:
1)Na2SO4 + 2H20 <===>2( Na+ + OH-) +(SO42- + 2H+)
2)H20<====> OH- + H+
Now you are adding OH- in second equation it will shift to the left. That means you have more water in your solution therefore you have more water in equation “1”then it will shift to the right that means more SO4-2. ( adding OH- , is not going to affect your first equation because Na2SO4 has much much bigger Keq compare to H2O)
omidvaram gerfteh bashi aziz, soale nesbatan sakhti bood. :)
 
About the Ads
This thread is more than 12 years old.

Your message may be considered spam for the following reasons:

  1. Your new thread title is very short, and likely is unhelpful.
  2. Your reply is very short and likely does not add anything to the thread.
  3. Your reply is very long and likely does not add anything to the thread.
  4. It is very likely that it does not need any further discussion and thus bumping it serves no purpose.
  5. Your message is mostly quotes or spoilers.
  6. Your reply has occurred very quickly after a previous reply and likely does not add anything to the thread.
  7. This thread is locked.