How much can an F decrease my chances of graduate school?

My grades, due to circumstances beyond my control, were not what they could have been for two semesters. I received an F in a course last semester, but I am currently retaking it and will likely receive a B, which will replace the F.

This semester, I am in a course where my grade will likely be a D or an F. With the little time I have left, I will likely not be retaking the course. Since it is a class that does not count toward my major nor general requirements, how much will it hinder my chances of graduate school?

Grad schools will want to know if the circumstances beyond your control will continue and hinder your performance in graduate school. They will also want the details of these circumstances.

From another post you indicated you are a sophomore. You still have two years to bring your GPA up. Get involved in research. Minimize the impact of the poor grade and be prepared to show that you are capable of the work. A stellar junior year will show what you are capable of.