Mate-in-One: Do you Remember This Trick?

Hello!  In each of these puzzles you will make checkmate in one move.  It is white's turn.  They will use a tricky move, for example "en passant".  Do you remember all the rules of chess?  Good luck!  By Mrs Jessica E Prescott (aka BoundingOwl).

 
2.  What if black's last move were b5??
 
I hope you remembered en passant!  Just play cxb6 and it's checkmate!
 
3.  Let's say the king and rook have never moved....
 
4.  This is perhaps a bit more common than the others.
 
5.  Here is another Super Pawn Puzzle!  Sometimes pawns turn into queens.  Other times...?
 
 
(Wait, what?!  Why don't you want to be a queen?)
 
Super job!  Remember, if something is pinned, point and laugh (and checkmate!)  You don't always have to do en passant because it's there; but you do always have to recognize that it's there.  Did you see it? Cool