Dickens is notably one of the best writers of description, so I would encourage you to open to most any page of the book to find some, besides you are asking two questions in one and that is not allowed. Thus, I will address this issue of irony.
Irony is a surprising twist of events. This occurs regularly throughout the story.
- It is ironic that the man Pip meets on the marshes has a great iron on his leg as Pip is a child living in a blacksmith's forge. (Chapters 1-3)
- Irony is a convict that is so rich that he may anonymously fund Pip's attempt to become a gentleman. (Chapter 40)
- Irony is high society Estella having parents of much less than noble social class in Magwitch and Molly. (Chapter 56)
- It is ironic that Pip's challenger in the pale young gentleman becomes his best friend Herbert Pocket later in the story. (Chapter 22)