I need answered in this paper What is the relationship between mass, moles, and

I need answered in this paper
What is the relationship between mass, moles, and molecular weights?
What is the unknown compound from the simulation and how did you determine the identity of the unknown compound? Describe the steps. we had a bottle with only a partail label that had 500g. of Cl.
What is a possible scenario where a nurse may need to use stoichiometric calculations?
The unknown compound was MgCl