Mistake, confuse, confound are comparable when they mean to mix up things, typically by taking one thing for another.
One mistakes one thing for another when by an error of perception or of thought or as a result of a predisposition or a bias one fails to recognize the thing or to comprehend its real nature and identifies it with something not itself or with something of another nature.
One confuses one thing with another when one fails to distinguish two things that have similarities or common characteristics or to observe their lines of demarcation.
One confounds things, or one thing with another, when one mixes them up so hopelessly that one cannot detect their differences or distinctions. Confound usually carries a stronger connotation of mental bewilderment or of a muddled mind than the preceding words and accordingly is often preferred when the differences are more or less obvious to a clearheaded or intelligent person.