Formula of a Chloride Lab

Yesterday we had a lab in class over the mass and formula of Zinc chloride. My partner and I did not pass our pre lab quiz unfortunately but that was simply because once we realized how we had to solve the equation we had ran out of time. We were then given data by our teacher and asked to find the amount of Cl in the starting substance. Having just practiced how to do this type of problem on the pre-lab quiz, finding this answer was quite simple.