Not too easy. Not too difficult.
Its nice to be able to go at your own pace, but you have to really apply and study. Sometimes I had to go to other sources to find answers.
They offer video tutorials on problems, these has helped my greatly. I've learned better studing techniques as well as the chemistry material.
Hours per week:
Advice for students:
You have to be willing to do the work. Its all at your own pace, so you can really apply and finish in a week, or if you procrastinate it might never get done. There is nothing besides yourself pushing you to do the work and finish.