It does matter if they play at home or not. If Chelsea were to play this game away against Arsenal, I think it would almost be certain that Arsenal would win the game, but since this isn't a home game for Arsenal, I think that it is possible for Chelsea to play a better game than they would otherwise. Whether that is enough for a win for them, I don't know. But playing in front of their own fans is at least supposed to be a different atmosphere for them that should help them to put more effort into that game.
Play home or away its not really difference atmosphere for Chelsea because last winning match from away when defeating Burnley, but Arsenal opponent is difference than Burnley with consistency performance and they have more confidence after last match before international break out success beaten defending champion of Premier League teams Manchester City.
Otherwise, Arsenal have more motivate take first position standings from other London team Tottenham Hotspur, have the same points with lack goals productive I think three points against Chelsea will move to the first position place for awhile due Tottenham Hotspur vs Fulham will play on Tuesday.
It is a difference and everyone who plays football or anything else knows that playing at home can make a hell of a difference. No single statistic that is not focusing on outliers will confirm that. Of course there are times when a team wins a few more games away than at home for a certain period. But if you look at any scientific investigation across all kinds of sports or statistical analysis specifically for the Premier League, the evidence for a home advantage to exist is significant.
and choose the statistics for different seasons, but there are also plenty of other websites that offer a great overview of the home advantage.