1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution There is 0.2 mol of Cl- ions so therefore this leaves us with a 1:1 ratio for the chloride ion to chromium ion in the complex ion. This leaves us with option B or D. However, I am not sure how to choose between them. Can someone give me some advice? Cheers!