AAS question help (1 Viewer)

[hungreypotter]

i dont really understand how to do this question so could someone explain. i looked at the sample answer but i don't get what they are trying to convey, the working out is kinda unclear.
thanks so much!

 

[STBAccuracy]

Was the solution A?

 

[STBAccuracy]

Was the solution A?

This is my working, with it getting A as a solution.

 

[Luukas.2]

The solution is 12.5 ppm in Cu²⁺ ions but the solid formed is CuCO₃.

The question is also implying that all of the copper can be precipitated as CuCO₃, which isn't true because there will be a solubility equilibrium, but almost all of it can be precipitated if enough carbonate is added without increasing the volume too much, and if K_sp(CuCO₃) is small.

 

[hungreypotter]

View attachment 39966This is my working, with it getting A as a solution.

the solutions said the answer was B for this question but im not sure how they got it lol

 

[STBAccuracy]

B was the correct solution, A is the mass of the Copper in the solid and is not the total mass of solid (I forgot the mass of the carbonate lol)

 

[hungreypotter]

B was the correct solution, A is the mass of the Copper in the solid and is not the total mass of solid (I forgot the mass of the carbonate lol)

thanks so much !!