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.
But the opportunity to score a goal for Tottenham is actually much easier. So I think in the Tottenham vs Fullham match we will see a lot of goals. There will be at least 3 to 4 goals in one match. So if Tottenham are able to get 3 points then they will maintain their current standings.
Meanwhile, Arsenal, who will face Chelsea at Stamford Bridge, also looks like they will be able to win the match. It's just that Arsenal might not be able to score many goals. Maybe there were only 1 or 2 goals in the match.
For Chelsea, currently they are really in a desperate position. And usually in a position like this there will be two possibilities. Are they worse off because they lack self-confidence or is it the opposite? They become more eager to change things and surprise their opponents.