How much you study outside of class will be largely dependent on your science background, your learning style, study methods, and memory. You will get widely varied answers depending on where people fall within those spectrums. I had little to no science background, I learn from reading, my study methods were inefficient, and my memory I would say is slightly above average. I spent about 35 hours a week outside of class on non-test weeks and 45 or more on test weeks. Now in second year, I study about 25 non-test and 35 test. That is mainly because I now have the science background and learn concepts much easier now, my study habits are better, and I don't have as much trouble listening in class anymore.