Chelsea vs. Nordsjaelland
This is fairly simple: Chelsea are three points behind Shakhtar and two points behind Juventus and have an inferior head-to-head record against both teams. In order to qualify, they'll have to hope that Shakhtar win against Juve and pick up three points themselves. Nordsjaelland have nothing to play for - they're already out of both the Champions League and the Europa League.
Shakhtar vs. Juventus
Again, simple: Shakhtar are already through but will want a draw or a win to claim first place in the group, while Juventus just need to avoid defeat to guarantee their progress to the next round. A win would see the Bianconeri take first place.
There's almost nothing to play for in this group, with BATE guaranteed third, Lille guaranteed to go home empty-handed, and Bayern and Valencia already through. It's a contest between those two for top spot in the group, and Bayern have the better head-to-head record, so all they need to do is equal or better Valencia's result against Lille in order to take first place.
Barcelona are guaranteed first place while Spartak Moscow are guaranteed last, so this is a straight fight between Benfica and Celtic for progression to the next round. Celtic face Spartak at home, while Barcelona are away at Benfica, so the advantage is with the Scots - although Benfica have the better head-to-head record. If Celtic can better their result, they'll go through, but if Benfica can pull off a win they'll guarantee their progression.
Much like Group G, Manchester United are guaranteed first and SC Braga are guaranteed last, so it comes down to a fight between Galatasaray and CFR Cluj for that second-place qualification spot. Galatasaray haven't qualified for the next round since 2002, and the Turkish side have the superior head-to-head record against CFR Cluj, so can progress simply by equalling or bettering their result. Gala are away against Braga, while Cluj face Manchester United at Old Trafford, but with the Red Devils through and likely to rest players ahead of the Manchester Derby, a Cluj win is not out of the question.