Pathfinder: CR questions

[Earlstoke]

I am running a one shot campaign for my play group. I will have 5 players. I want them to be level 10 for this one shot. I want some to die and some to survive, for my big bad i am thinking about a CR 14. Will this be too much for them to possibly survive? I have never done a 1 shot like this so any help would be appreciated.

[awa]

it depends on a lot of stuff for example the optimization of the party. Some low op parties have trouble with "appropriate threats" some high op parties can smash a cr+4 monster with triveal ease
Second not all monsters some monster are really strong for their cr others are weak. Are they going to be fighting this foe after going through a dungeons expending spells and hp or are they going into the fight forewarned having selected abilities to specifically counter the boss.
On top of all that some monsters are particularly strong or weak against certain types of foes constructs laugh at sneak attack and giants tend to be very weak against wizards (as in more so then normal)

So I suppose the answer to your question is maybe give us more info