Exam+1+Key+SS2+_02

Exam+1+Key+SS2+_02 - Chem 2B Exam 1 Key, SS-2, 2002 Chem...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chem 2B Exam 1 Key, SS-2, 2002 1 Chem 2B: Exam 1 Key: Summer Session II, 2002 Part I: Multiple Choice, Concept and Short Calculations, 130 pts - No Partial Credit 1.(15 pts) Consider the generalized phase diagram below: Label the five indicated features from the following: boiling point melting point critical point saturation point solid amorphous crystalline liquid vapor metal aqueous freezing point triple point sublimation vaporization polymer solution expansion A) ___________vapor_______________ B) ____________liquid______________ C) ____________solid_______________ D) ___________triple point___________ E) ___________critical point__________ 2.(10 pts) For the substance whose phase diagram is presented in question one, which of the following is true: a) The enthalpy of vaporization is less than zero. b) The enthalpy of fusion is less than zero. c) The enthalpy of sublimation is less than zero. d) The density of the liquid is greater than that of the solid. e) The density of the liquid is less than that of the solid. T P A B C D E
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chem 2B Exam 1 Key, SS-2, 2002 2 3. (10 pts) What are the number of atoms per unit cell and the coordination number (CN) for a body centered cubic lattice? a. 8 atoms; CN = 12 Corners: 8 * 1/8 = 1 b. 2 atoms; CN = 8 plus Center = 1 c. 2 atoms; CN = 12 d. 1 atom; CN = 6 e. 4 atoms; CN = 12 4. (10 pts) Calculate U for a system that absorbs 315 J of heat and expands from a volume of 6 L to 10 L against a constant pressure of 150. kPa (Remember: 1 L•kPa = 1 J). a. –915 kJ b. +285 kJ c. +915 kJ d. -285 kJ e. Not enough information to calculate. U = q + w = q - P V = +315 + (-150 * 4) 5. (10 pts) The boiling point of NH 3 is higher than CH 4 due to a) ion-ion forces. b) hydrogen bonding. c) special ops forces. d) dipole-dipole forces. e) London forces. 6. (10 pts) In a closed container, a liquid and its vapor reach a dynamic equilibrium. Which one of the following statements is true at equilibrium? a. Energy is transferred from the surroundings to the gas.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 8

Exam+1+Key+SS2+_02 - Chem 2B Exam 1 Key, SS-2, 2002 Chem...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online