Alienate is synonymous to separate. So it will alienate them from the group
well since they deleted my answer, you're on your own kid. Goggle it, you will find the answer right away.
Shakespeare builds tension in the play by having the witches mysteriously appear and dissapear. Through dramatic irony he is giving the audience more information about the witches then the characters. They are thinking whether to trust the witches or not, but we already know that they shouldn’t.
