Greetings,
maxcai6179:, I'd like to welcome you and all the new students to the Chemical Forums. But I'd like to as you to trouble yourself to read our
Forum Rules{click}. You already accepted them when you signed up for our forum, and they apply to you, whether you agree with them or not, or even if you're unaware of them.
We want to see your work, and then, we want to give you hints, so that you learn for yourself. Unfortunately, you have provided us with no context at all for your question. There's no way to solve it, as written. For example, 'Co' is listed in the periodic table for the element Cobalt. That's international shorthand all chemists understand. The '(en)' can mean anything. The word 'resolve' is likewise jargon for your application. And we have no idea what steps came before or after the NaOH addition.
Why not try to summarize you application and tasks, and see if you maybe even solve it for your self? Or at least get closer than -- "No clue at all, I do not know where to start. Please, *delete me*!"