[akxt]

1. What is the concentration of silver(I)ion in a saturated solution of silver(I) carbonate containing .0022M Na2CO3. For Ag2CO3, Ksp=8.6*10^-12

I set up an ice table for Ag2CO3 <-> 2Ag+ + CO3 2-

(8.6*10^-12) = [2x]^2[.0022]

The 2x is supposed to be there right? if i drop the 2.. I get the correct answer for x, which is 6.3*10^-5..
but i don't think im supposed to just drop it.. ?? am i missing something here?

2. What is the concentration of HC2O4- in a .270M oxalic acid, H2C2O4? For Oxalic acid, Ka1 = 5.6*10^-2 and Ka2=5.1*10^-5.

So I set up two reactions
a)H2C2O4 + H2O - > H3O+ + HC2O4-
b)HC2O4- + H20 - > H3O+ + C2O4^(2-)

I solved for x in a) and got x = .123
then i set the .123 as the initial concentration for b) HC2O4- and solved for y but keep getting 1.2*10^-1. Answer key says 9.8*10^-2.

3. Suppose NaOH is added to .0099M solution of zinc nitrate such that the pH of the solution is 13.19. What is the eq. concentration of Zn2+ ?

The formation reaction for Zn(OH4)-2 is given and Kf = 2.8*10^15..

I wrote it the other way and wrote down Kd = (1/Kf)

I set the complex ion initial concentration as .0099 and Zn2+ as 0 and 4OH- as .15 ((got .15 from calculating [OH]- from the ph 13.19 given)) Proceeded and got the wrong answer

Someone please *delete me*! I have an exam tomorrow (questions given today for practice)

[AWK]

2. What is the concentration of HC2O4- in a .270M oxalic acid, H2C2O4? For Oxalic acid, Ka1 = 5.6*10^-2 and Ka2=5.1*10^-5.

So I set up two reactions
a)H2C2O4 + H2O - > H3O+ + HC2O4-
b)HC2O4- + H20 - > H3O+ + C2O4^(2-)

I solved for x in a) and got x = .123
then i set the .123  as the initial concentration for b) HC2O4- and solved for y but keep getting 1.2*10^-1. Answer key says 9.8*10^-2.

Initial concentration is 0.270 M
Use quadratic equation based only on Ka1

3. Suppose NaOH is added to .0099M solution of zinc nitrate such that the pH of the solution is 13.19. What is the eq. concentration of Zn2+ ?

The formation reaction for Zn(OH4)-2 is given and Kf = 2.8*10^15..

I wrote it the other way and wrote down Kd = (1/Kf)

I set the complex ion initial concentration as .0099 and Zn2+ as 0 and 4OH- as .15 ((got .15 from calculating [OH]- from the ph 13.19 given)) Proceeded and got the wrong answer

3. Suppose NaOH is added to .0099M solution of zinc nitrate such that the pH of the solution is 13.19. What is the eq. concentration of Zn2+ ?

The formation reaction for Zn(OH4)-2 is given and Kf = 2.8*10^15..

I wrote it the other way and wrote down Kd = (1/Kf)

I set the complex ion initial concentration as .0099 and Zn2+ as 0 and 4OH- as .15 ((got .15 from calculating [OH]- from the ph 13.19 given)) Proceeded and got the wrong answer

I cannot check your calculations

[Borek]

1. What is the concentration of silver(I)ion in a saturated solution of silver(I) carbonate containing .0022M Na2CO3. For Ag2CO3, Ksp=8.6*10^-12

I set up an ice table for Ag2CO3 <-> 2Ag+ + CO3 2-

(8.6*10^-12) = [2x]^2[.0022]

The 2x is supposed to be there right? if i drop the 2.. I get the correct answer for x, which is 6.3*10^-5..
but i don't think im supposed to just drop it.. ?? am i missing something here?

All depends on what x is - it can be Ag⁺ concentration, it can be Ag₂CO₃ solubility. Not knowing what and how you did it is hard to say whether you should put 2 or not. However, if you have used just Ksp equation (seems you did) x stands just for [Ag⁺].

I can't see where you have used ICE table here.

2. What is the concentration of HC2O4- in a .270M oxalic acid, H2C2O4? For Oxalic acid, Ka1 = 5.6*10^-2 and Ka2=5.1*10^-5.

So I set up two reactions
a)H2C2O4 + H2O - > H3O+ + HC2O4-
b)HC2O4- + H20 - > H3O+ + C2O4^(2-)

I solved for x in a) and got x = .123
then i set the .123 as the initial concentration for b) HC2O4- and solved for y but keep getting 1.2*10^-1. Answer key says 9.8*10^-2.

Sorry - I am not a mindreader. I have no idea what x and y are. You must be more specific.

3. Suppose NaOH is added to .0099M solution of zinc nitrate such that the pH of the solution is 13.19. What is the eq. concentration of Zn2+ ?

The formation reaction for Zn(OH4)-2 is given and Kf = 2.8*10^15..

I wrote it the other way and wrote down Kd = (1/Kf)

I set the complex ion initial concentration as .0099 and Zn2+ as 0 and 4OH- as .15 ((got .15 from calculating [OH]- from the ph 13.19 given)) Proceeded and got the wrong answer

Approach seems correct (no idea why you prefer to use Kd instead of Kf - it boils to exactly the same - but that should not interfere with the final result). Not seeing your calculations it is hard to say what went wrong.