I doubt that Arsenal can win this round, indeed both teams still have the same chance, but in the next match Arsenal will face Munich away, of course this will make Arsenal feel pressured and I'm not sure that even if Arsenal uses all their strength, Munich will also do the same thing, let alone competing at home will make Munich more confident to win.
Actually there's also some amount of pressure on Munich too to achieve a victory in the game but then I'm very optimistic about Arsenals performance in that they seem to have a good level of confidence in their recent form considering all the games they have been able to win an their performance against Munich which got them a draw was actually not an easy game even for Munich aswell.
In their second leg Munich will be playing from home and that is actually looking like a good advantage but then Munich hasn't bee consistent enough to really differentiate their home performance from their away performance which will be much better than the other but then they will literally have to improve their performance if they wish to still continue in the champions league again because Arsenal is really bent on winning and they have got a fair strength with their attack although Munich as also got a sharp attacking tactics but then Arsenal Also still have a fair defense too.
Arsenal has also got pressure from the premier league too which will actually affect them in a way because they will be trying to maintain their spot on the top of the table in the premier league for a possible opportunity to end up lifting the premier league title this season but then Liverpool is Also relentless about the title too so i feel for Arsenal it's not going to be really easy as they have a lot to tackle already.