It depends on what you'd like to use it for. C++ is almost exclusively used to make video games, so if you're interested in game programming, then that's the way to go.
Java is more widely used in industry, as it is used in the financial industry and also is the main programming language for all Android devices.
As a chemistry major, the most useful language to you right now would probably be R, a statistical analysis language, or something functional, like Haskell. Python would also suit you well. It's very popular right now in many, many industries. However, none of those seem to be options.
Honestly, it's pretty split. My advice would be to choose based on which professor you think you'll like better or which projects sound more interesting.