Hello! I'm currently working on a lab report and I'm lost. I reviewed the book and looked for similar problems,but I can't seem to understand the...

Hello! I'm currently working on a lab report and I'm lost. I reviewed the book and looked for similar problems,but I can't seem to understand the concept. The problem states " Calculate the amount of red crystals you produced in moles." I know what the actual yield is in grams (0.72 g),but I'm a bit confused on where to go from here.