Notice that the top question is actually almost a year and a half old and was bumped to the top due to an edit, while the other questions you're comparing to are less than an hour old.
Furthermore, it is very natural that some questions get a massive amount of views from search engine hits, and this can happen even if they don't have great answers or a lot of votes. You'll find these to usually have very basic general aspects of chemistry, or deal about some everyday phenomenon, or involve some simple homework-y type content covered by most people in high school. For example, look at the question "Why is gold golden?", which has amassed almost as many views in only six months.
There is one more thing to consider; some questions get featured among the "hot network questions", a few of which are often displayed on the right of the page. Chem.SE is only a small fragment of a tremendously huge congregation of StackExchange sites (which put together represent one of the top 200 sites of the web in traffic), so even if only 0.01% of users at a completely unrelated but large SE site such as StackOverflow lay their eyes on a Chem.SE question among the hot network questions and decide to click, views can easily accumulate tens of times more quickly compared to regular traffic here.