[Daimorte]

Could somone explain me how would sodium alazarin sulfate react with cobalt chloride? I have only learnt the basics of organic chemistry...so I don't think I will understand very long and scientific explenation.

[D|0XIN]

Do you know specifically what the formula of cobalt chloride (eg. CoCl₂) is that you're dealing with / asked?

i) Cobalt(III) could possibly oxidise alizarin, which would result in decolouring of this intensely red dye, and production of Co(II) [Co²⁺:      Co³⁺_(aq) + e^- --> Co²⁺_(aq)   Co³⁺ is the oxidant and is itself reduced

or (my best bet):

ii) Cobalt(II or III?) chloride dissolved in water is providing Co²⁺ or Co³⁺ which may form a co-ordination complex with alizarin (the sodium part doesn't matter - its only the counter-ion there to balance charge).

[Daimorte]

It's Co⁺³, I know it because of the red  coloring, it was given in the task, thank you very much!