CHEM 210 MODULE 2 EXAM – WITH CORRECT ANSWES- DOWNLOAD TO SCORE AN A+

CHEM 210 MODULE 2 EXAM – WITH CORRECT ANSWES- DOWNLOAD TO SCORE AN A+ The following reaction occurs in glues purchased from hardware stores. Customers use this product to glue plastic together. Epoxy (l) + hardener (l) Glue (s) + heat given off What is the sign (+ or -) of the change in G and H? A) G is (+) and H is (-) B) G is (-) and H is (-) C) G is (-) and H is (+) D) G is (+) and H is (+) E) None of the above A Correct! B C D E Question 21 3 / 3 pts Scientific Calculator ( A pH = 5.0 indicates a concentration of OH- (in M) of . A. 5 B. 10-5 C. 10-9 D. 10-1 E. 101 A B Correct! C D E Question 26 5 / 5 pts (Short Response) How does the strength of a hydrogen bond compare to the strength of a London Force? Also, how about the strength of a hydrogen bond compared to a dipole-dipole force? Briefly comment on these differences. Your Answer: The strength of a hydrogen bond is 14 kcal while a London force is closer to XX kcal. The strength of a hydrogen bond is much greater than that of a dipole-dipole force, which is closer to XX kcal though it is the second strongest noncovalent force. The differences between these forces is that a hydrogen bond is the strongest non covalent forces. The hydrogen bond strength is between 12 and 16 kcal, while the London force is generally less than 1 Kcal. A dipole-dipole bond usually is from 0.5 to 2.0 kcal. Also, hydrogen bonds are the strongest non-covalent force, which is illustrated by these numbers. Question 27 5 / 5 pts Scientific Calculator ( Your Answer: The Ka can be calculated by [X-][H+] / [HX] [0.32][0.32] / [0.051] The Ka = 2.007 or 2 (Fill in the blanks) At cool temperatures, water vapor turns into liquid water releasing heat in the process. Fill in the missing blanks, below, regarding this process. Please identify your answers by writing “A.” then your answer, “B” then your answer, and so forth. The free-energy change, G, has a A value (choose “+” or “-“). The enthalpy change, B (fill in symbol), has a C value (choose “+” or “-“). The D change, ( S), has a E value (choose “+” or “-“). Your Answer: A. (-) B. delta H C. (-) D. entropy E. (-) A) “-“ B) H C) “-“ D) entropy E) “-” Question 30 5 / 5 pts Support or refute this statement: The following diagram shows a clathrate. (Write “Support” or “Refute,” and then explain in at least two sentences providing one piece of evidence for your answer.) Your Answer: