Question

12. Reflux is the process of turning liquid into vapor. a. b. the process of changing a solid to a gas without ever passing through a liquid phase the process of boiling a liquid in such a way that any vapor is liquefied and returned to the flask. the physical process that results in the phase transition of a substance from a solid to a liquid. c. d. 13. If a student was going to react 4.88 g of potassium hydrogen phthalate (KHP) with excess HCI, how much phthalic acid would be produced in the reaction? a. 4.70 g b. 47.0 g c. 5.06 g d. 50.6 g ?? O-H O-K 14. Which of the following techniques is used to test the purity of a chemical sample? a. Suzuki Coupling b. Dynamic mechanical analysis c. UV-visible spectroscopy d. Melting point determination

Answer 1

12. Option C is correct.

Because Reflux is a technique involving the condensation of vapors and the return of this condensate to the system from which it originated

13.

From stoichiometric equation we can say

204.22 grams of KHP produce 166.14 grams of pthalic acid.

then 4.88 grams of KHP produce how much amount of pthalic acid?

= (4.88*166.14)/204.22

= 3.97 grams it is about 4 grams..

So the answer is option A.

14. option B is correct. Because Dynamic mechanical analysis (abbreviated DMA, also known as dynamic mechanical spectroscopy) is a technique used to study and characterize materials.