[Tineke]

I need to calculate the solability of CuI in a 1,0*10^⁻4 Mol/l K -solution, knowing that Ksp(CuI)=1,1*10^-12 and K_s2 of the reaction:
CuI(s)+I CuI2−=7,9⋅10^⁻4

I have already figured out that the solid CuI will partially disolve by complex forming, which will shift the precipitation reaction to the right.

I learned to solve this with a lineair system. But I only got a first equation:
CuI2−CuI⋅104= 7,9⋅10^⁻4

According to my textbook the final answer is: 9,0*10^⁻8 Mol/l

Can someone please help me out

[Borek]

I learned to solve this with a lineair system.

There will be definitely system of equations, but it won't be linear.

But I only got a first equation:
CuI2−CuI⋅104= 7,9⋅10^⁻4

No idea what you are trying to do/say here, please elaborate.

Please note you can use the formatting buttons above the edit field to write things like CuI₂^- and 7.9×10^-4, makes it much easier to follow what you wrote. Or even use LaTeX (About post formatting...).

[mjc123]

in a 1,0*10^⁻4 Mol/l K -solution

Do you mean a 1.0*10^-4 mol/L KI solution?