The population of San Francisco is 750,000 in an area of 49 square miles. What is the population density in San Francisco? Express your answer in people per acre. ( 1mi(squared) = 640 acres )

49 sq mi x (640 acres/1 sq mi) =?? acres. (Note that sq mi cancels leaving acres.)

density = People/acre.
density = 750,000/?? acres (from above.)
I hope this helps. By the way, this is more a math than a chemistry problem although we do deal with density in chemistry (and physics and bilogy and etc.)

Well, it came from my Chemistry class so that's why I labeled it Chemistry. But thanks for the help.

I guess they were trying to make the problem more personal by using population and not grams and cc. Post anytime under any heading.

No problem! I apologize for assuming it was a math problem. It's great that you're applying concepts from chemistry to real-world situations. If you have any other questions or need further assistance in any subject, feel free to ask!