How do I find the density of pentadecane?
#"0.7687 g/cm"^3#at #20^@ "C"#
I use this as a university student and I find it useful and reliable, especially since they even give melting point and boiling point ranges determined by multiple sources, not just singular values.
Alternatively, looking up the "MSDS" (more recently changed to just an SDS) is always a good idea. Besides on Sigma Aldrich, I found an SDS for pentadecane here. It shows:
#"0.769 g/cm"^3#at #20^@ "C"#
And remember that it's a good idea to check multiple sources to see if their densities agree. I found other sources that had "relative" densities like