It is not "impossible" for Liverpool to win the title, there is a 15 point difference and it's not something that can't be covered but lets be honest and just realize that it won't happen. We have seen Liverpool trail City with just 1-2 points and still lose because City refused to lose points, hence they kept winning and Liverpool ended up with points that would have been champions in most years, became second in those years because of Cities record breaking point championships.
All in all I think City will get it again, even though Arsenal is at the top, I still would bet on City to get it because they are a much more consistent team when it comes to winning games in premier league.
In fact, I think this is impossible with the conditions of the EPL, which are always competitive and the consistency of Manchester City, especially seeing them only lose 3 last season, so I think this is very difficult for Liverpool.
At the moment they at least have to hope that some of the big teams above them continue to lose at least 5 times when they win and this is of course not easy