A molecular formula can be also called as chemical formula, an expression about constitute elements of a chemical compound.
In the translation work concerning chemical and medicine, molecular formula is common. Generally the name is given together with the molecular. In such case, translators could just look up the word in a dictionary or a translation memory or with other translation assistant tools. That is very easy to get a translation unless the word is quite uncommon.
E.g. 硝酸乙酯 C2H5ONO2 ethyl nitrate
Just look up the name “硝酸乙酯” of the molecular formula in a dictionary and you can get its translation in no time.
However, what if only a molecular formula is given?
For common molecular formulas, such as H2O, H2, O2, CO and CO2, if you search on the internet and you could get desire results, too. Even longer molecular formula can be translated in this way. For example, OCH2CHCH2Cl, if you copy it to search field of a translation tool or a search engine, all the subscripts turns to normal scripts (i.e. OCH2CHCH2Cl) in the search field. As you see, the string changes but you can still get your answer. It is “环氧氯丙烷”, then you can get the translation “epichlorohydrin”.
But some molecular formulas, the translation could not be achieved in the way above. And I got a suggestion for that.
Take CH3CH2CH2CH3 for example, you visit the home page of Wikipedia in English, and enter “C4H10” in the search field which do not support subscripts. And “C4H10” is obtained the adding of all “C”s and “H”s in the molecular respectively. Then press ENTER and wiki will return two results: butane and isobutane. And you can click the two hyperlinks and decide the specific name of “CH3CH2CH2CH3”: butane.
You may be confused that why C4H10 represents two molecules. Even molecules composed of the same quantity of the same elements might be quite different from each other in chemical and/or physical properties due to different structural connections.