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Topic: Changes to a solution at equilibrium?  (Read 3008 times)

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Offline calaren

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Changes to a solution at equilibrium?
« on: January 30, 2011, 08:48:11 PM »
Here goes...
I'm working on my U Chem II homework and I'm stuck on the last 2 parts of the last problem. Here they are exactly as written:

You are given a saturated MnCO3 solution at equilibrium.
D. Upon addition on 3M HCl, what will happen to the concentration of Mn2+(aq)? Hint: What do acids and carbonates do?

E. Upon addition of 0.5M AgNO3, what will happen to the molar solubility of MnCO3? Hint: What will happen when Ag+ and CO32- are mixed (think Ksp)?

OK, for part D, I know that carbonates neutralize acids - so does that mean that the concentration of Mn2+(aq) will go up since some of the carbonate is going to neutralize the HCl?

For part E, I haven't got a clue - if someone could gently nudge me in the right direction, I'd be so thankful!!

"Chemistry has been termed by the physicist as the messy part of physics, but that is no reason why the physicists should be permitted to make a mess of chemistry when they invade it."
Frederick Soddy

Offline opti384

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Re: Changes to a solution at equilibrium?
« Reply #1 on: January 30, 2011, 11:26:12 PM »
Ag2CO3 will precipitate.

Offline rabolisk

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Re: Changes to a solution at equilibrium?
« Reply #2 on: January 31, 2011, 01:03:47 AM »
For E, there are two simultaneous "reactions" going on.

MnCO3  ::equil:: Mn2+ + CO32- and
Ag2CO3  ::equil:: 2 Ag+ + CO32-

both with their own individual Ksp that are not affected by each other. But while the constants are unaffected, both have carbonate.

Offline calaren

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Re: Changes to a solution at equilibrium?
« Reply #3 on: January 31, 2011, 08:58:38 AM »
Rabolisk,
It's Ag2NO3 - sorry!
"Chemistry has been termed by the physicist as the messy part of physics, but that is no reason why the physicists should be permitted to make a mess of chemistry when they invade it."
Frederick Soddy

Offline rabolisk

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Re: Changes to a solution at equilibrium?
« Reply #4 on: January 31, 2011, 09:31:47 AM »
My post was not a mistake. AgNO3 is added but there is no equilibrium going on there because it is a nitrate.

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