I agree with you that Barcelona will win against Napoli in the second leg of the UEFA Champions League Round of 16 matches. Napoli's performance against Barcelona was poor. Napoli just managed to have one shot on target against Barcelona, which led to a goal that earned them a draw. With Napoli's present form, it will be hard for them to beat Barcelona at Camp Nou.
Barcelona's condition this season is also no better compared to last season, so Barcelona itself will not win easily at home. Because Napoli will also try to do better at home to Barcelona in the second leg even though both of them already have one goal in the first leg. In the Champions League there are always unexpected things that happen so that victory for any team will not be easier, including for the home team like Barcelona.