[chita]

Hi, can anyone help me with this problem?

Data:
pKs (PbSO4) = 7,8
pKs (PbF2) = 7,5
PbSO4 = 0,05 M
How much NaF do I have to add (quantitative conversion to PbF2)?

I've found 0,17 g (NaF), is it correct?

Thanks

[AWK]

Not Sufficient data. Moreover 0.05 M PbSO4 is an impossible concentration.
Maximum concentration in water is ~0.0002 M

[chita]

Thanks, I will ask to professor

Can you help me with this problem?

Calculate the solubility of Ag2S in KCN 0,1M
Ks (Ag2S)=7*10^(-50)
Ag+ + 2CN- <-----> [Ag(CN)2]-  K=10^(20)
H2S Ka1=10^(-7) Ka2=10^(-13)
HCN Ka=10^(-9,6)

[Borek]

You have to show your attempts at solving the problem, it is a forum policy.

[chita]

I've found solubility=9,57*10^(-5)

But I'm not sure because I have not the result

Thank you

[billnotgatez]

@chita

Just because you have an answer does not mean someone can help you unless you show how you got the answer.
All is explained in the forum rules.
Click on the link near the top center of the forum page.
Forum Rules: Read This Before Posting.
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