Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

QUESTION 5 You are given a sample of benzoin that has been contaminated with ant

ID: 714045 • Letter: Q

Question

QUESTION 5 You are given a sample of benzoin that has been contaminated with anthracene and you purify this sample by recrystallization. Which of the following is a possible melting point you may measure if you did successfully purify benzoin? (literature melting points: benzoin 134-138C: anthracene 210-215C). 172-175C O 210-212 C 134-136 C 120-130 C 135 C QUESTION6 You are given a sample of benzoin that has been contaminated with anthracene and you purify this sample by recrystallization. Which of the following is a possible melting point you may measure if you did not successfully purify benzoin and it is still contaminated with anthracene? (literature melting points: benzoin 134-138C anthracene 210-215 172-175 C 120-130C 135-140 C O 210-212 C

Explanation / Answer

5. Since benzoin is purified successfully, so the melting point of pure sample should be in the range of literature melting point of benzoin.

So, the correct option is 134-136

6. In general , a solid substance containing soluble impurity have lower melting point than the pure solid. This is called melting point depression .

Since , in this case the sample is not pure, so melting point of contaminated benzoin should be less than 134-138.

So the correct option is 120 - 130