"Meu entendimento é que esse livro é essencial para o estudo de química."
Can "que esse livro" here also translate to "that that book"? I know "that that" is a valid english construction and that "esse" translates usually as that. Is this translation of "that this book" correct?
Yup. esse means something close to the person you're talking to, and this person may be close to you. Maybe the person is holding the book and you ask: que livro é esse? (what book is this?). That (aquele, aquela, aquilo) would be something far from the speaker and listener... but i know... duo has been mixing their usages!!
Thanks for that! :) It's much clearer now. It's just hard to guess what they expect from you.