At the beginning of each trimester students are given a checklist to track their own mastery. As they progress through the lessons, they mark off what they have completed, in addition to the grade they received on each lesson. This acts as planner, letting students know at any given moment what they have completed, and what is left for them to learn to finish the trimester.
I have weekly check-in's with students about how they are progressing through the lessons. This ensure face-to-face time with each student and allows me to hold them accountable to the goals they are setting. I ask a standard set of questions "What lesson are you on today?", "What lesson do you plan on being on in a week" ,"Is there anything you need to help you reach your goal?" I record all their answers and keep a running log so I can refer back to these notes each time I conference with a student.
To give students greater independence, there is an answer key for the practice problems of every lesson. I know what a lot of teachers are thinking at this point: what if the student just copy all their answers from the answer key? As an Algebra teacher told me when I asked them the same question before starting flipped mastery, they'll just fail the mastery quiz. It only takes a few correctional assignments for them to realize that the answer key is there to check answers, not copy them.
Chemistry is a combination of the comprehension of scientific content and the application of mathematics to those concepts. My students have to be prepared to think deeply about difficult concepts the minute they step into my room. Starting the class with a relevant "Catalyst" helps them initiate their own thinking processes in preparation for a productive day in the same way that biological enzymes catalyze chemical reactions. During The Catalyst, I model my thinking process for how to approach a mathematical problem by having my students identify the key steps in the calculation and establish a foundation that students who struggle with math can fall back on when they're confused.