I do not understand why you are attending a college that doesn't offer the degree you wish to achieve.
But, that's your business.
Of course a BS in Chemistry is best, as chemistry is a science.
A BA, is a bachelor of arts degree. That would work best if you only intended to be a chemistry teacher, or not work directly with chemistry as a real scientist. (researcher, for example).
Maybe, for example, you were going to ge for a PhD in Medicine, then a BA would be fine too.
I'm no expert, but I think the difference between a BA, and BS often is less than two classes, perhaps higher math, and extra chemistry classes, make the degree BS, over BA.
With a BA, you take a couple extra "liberal arts" classes, rather than the math, or science courses.
It should not make too much difference with employers, who are looking for other requirements than just the fact that you earned your BA, or BS.
Often previous job experience, and your actual GPA is more important for an employer in a chemistry type industry.
Because each employer will also train you, do on-the-job training. They want to know that you are a fast learner, that's critical, and that you are a team player, able to get along with others, for example.
BUT, if you plan to later continue as a Chemistry major to get an MS degree, then it shouldn't matter that you had a BA first.
The requirements to get the MS would apply for your graduate level degree, and the BA degree wouldn't affect it.