[battleofsat]

i added NaOH to my solution (i know the anion is I^-), the color turned pink.
i then added Na₂CO₃ to the same (fresh/new) solution, the solution turned colorless.
the aqueous solution of my original compound is yellow.
what is the cation? is it one of  NH₄⁺, Na⁺, Li⁺, and K⁺.

attempts: i know the cation is one of the above because they are insoluble in OH^- and CO₃^2-, but I don't get the color change part?

ps: i have another compound, i determined the anion as Br^-, and i did the same cation tests including OH^- and CO₃^2-, but there weren't color change?...

 

[Hunter2]

All the cation you mentioned are colorless. Pink must be come from something else. Maybe impurities or indicator phenolphthalein.

And why do you think these cation are insoluble in Hydroxide or Carbonate? The opposite is the case. Ammonium you should smell as ammonia if getting alkaline.

[battleofsat]

ohh! thank you! and i meant soluble! oopsy