How does one obtain an appropriate mixture of methanol and water for recrystallization a solids sample?

re crystallization is a purification technique for solid compounds.

to perform re crystallization, an impure solid compound is mixed with hot solvent to form a saturated solution. as this solution cools, the solubility of the compound decreases, and pure crystals grow from solution.

re crystallization is often used as a final step after other separation methods such as extraction, or column chromatography. re crystallization may also be used to separate two compounds with very different solubility properties. this video will illustrate solvent selection for re crystallization, purification of an organic compound from solution, and will introduce a few applications in chemistry, thus the general melting point of mixture is always lower than melting point of pure compound

personal, she chose to do it.

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.