1) Yes it is (for example)
2) They are in Russia (for example)
3) Her name is Julia (for example)
4)No he isn't (for example)
1) It's my friend's bag (for example)
2) It's my father's textbook (for example)
3) It is my grandma's flat (for example)
4) They are my friend's parents/ My friend's parents are workers (for example)
5) These pictures are mine (for example)