Issue #33592: Alkanes sum formula error
Sum formula in the game is given as HnCn.
This is wrong for a number of reasons:
1) A compound that consists only of carbon and hydrogen (i.e. a hydrocarbon) always has an even number of hydrogen atoms.
2) A saturated hydrocarbon (that's what alkanes are) always has more hydrogen atoms than carbon atoms.
3) According to a IUPAC rule, sum formulas should list the individual elements in alphabetical order. This is not strictly followed in general chemistry (IUPAC rules are just recommendations, and not all of them have been adopted by the scientific community), but it is in organic chemistry, for a simple reason: For scientific use, sum formulas of organic compounds are almost entirely useless. Their main purpose is for computing lists, e.g. in the catalogues of chemicals suppliers (companies like Aldrich have several thousands of chemicals to offer) and databases (such as the CAS database). In that specific case, the rule comes in handy.
The correct sum formula of alkanes is CnH(2n+2).