Well, lets start working on your question stepwise, so you learn more, and are ready for the next question of this type. Can you write your reactants as chemical formulas? EDTA is a little complicated, so you can skip that one. But the formula of bismuth subnitrate, what is it? And how does your particular problem relate it to EDTA? I'm asking for a balanced chemical reaction here, again, you can just abbreviate EDTA for now.
Anyhow, a question for you, from me.
Downtown Manhattan, how do I get there, from where I am? What are the exact times for the subways?
Not a very good question, I've asked there, is it? I haven't even bothered to tell you where I've started from. And I want the most specific information. That is, in some ways, what your question looks like. So try to think it through, and ask a complete question.