A process is carried out in which a mixture containing 25.0 wt% methanol, 42.5% ethanol, and the balance water is separated into two fractions. A technician draws and analyzes samples of both product streams and reports that one stream contains 39.8% methanol and 31.5% ethanol and the other contains 19.7% methanol and 41.2% ethanol. You examine the reported figures and tell the technician that they must be wrong and that stream analyses should be carried out again. (a) Prove your statement.
(b) How many streams do you ask the technician to analyze?

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.