in/of

[aachu]

Which of the following sentences is correct?
1- You must read chapter five of your book.
2- You must read chapter five in your chapter.

If both are correct, which of the two (in, of) looks natural and why?

[billmcd]

Which of the following sentences is correct?
1- You must read chapter five of your book.
2- You must read chapter five in your chapter.

If both are correct, which of the two (in, of) looks natural and why?

I would use "in".