why the answer said cu2+ is yellow?

it should be blue right?

I can’t really see the image but
cu2+ has a green flame
And forms light blue precipitate with sodium hydroxide s

it should be blue right?

the question is asking when a yellow solution forms after dissolving A in a minimum volume of conc hcl, what is the cation in A, there are 2 possible answers which are Fe3+ and cu2+, I know the color of Fe3+ is yellow, but why Cu2+ is also a possible answer

I’m pretty sure fe3+ isn’t yellow
I think it’s reddish brown

it should be blue right?

The aqueous transition metal complex formed is [CuCl4]2- . This complex is a yellow solution. In this complex, Cu2+ is the cation.

No, the copper atom forms part of the complex anion, tetrachlorocuprate(II)

isn't that the same compound, in which Cu2+ is the central metal ion?

Yes, but in this case the copper(II) is part of an anion, it is not a cation.

ahh, okay, makes sense, thank you! but if Cu2+ is positively charged, which it is, isn't it still technically a cation? I don't know myself, just wondering!

I can see your dilemma.

Copper, in this instance, is simply an atom. We can use the model of oxidation numbers to ascribe it an oxidation number of +2, but it is the actual species that has a charge, not the copper. The confusion is compounded by textbooks, that can refer to the copper as being Cu²⁺, when it is nothing of the sort.

To offer an analogy, you would not describe the sulfur atom in a sulfate ion as having a charge of +6, or describe it as a cation.