Chem Practice Exam 2-1 Answers

Chem Practice Exam 2-1 Answers - CHEM 6B PRACTICE EXAM...

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

View Full Document Right Arrow Icon
Chem 6B Practice Exam 2A 1 - A Prof. Crowell CHEM 6B PRACTICE EXAM 2A (Prof. Crowell) Wtr 2008 Feb. 8, 2008 *** FILL IN YOUR STUDENT ID NUMBER , NAME , and TEST FORM = A *** Bubble in the correct response on scantron (26 questions, worth 4 pts each) 1. The phase diagram for CO 2 is given below. The triple point is at 5.1 atm and 217 K. What happens if carbon dioxide at 50 ° C and 35 atm is suddenly brought to 1 atm? a). The liquid and solid are in equilibrium. *b). The solid vaporizes. c). The solid melts. d). The solid and vapor are in equilibrium. e). The solid remains stable. 2. Hydrogen peroxide (H 2 O 2 ) is a powerful oxidizing agent used in concentrated solution in rocket fuels and in dilute solution as a hair bleach. An aqueous solution of H 2 O 2 is 30.0 % by mass and has a density of 1.11 g/mL. Calculate its molarity (in mol/L). a). 0.013 *b). 9.79 c). 8.8 d). 12.6 e). 300 3. The vapor pressure of methanol at 25 ° C is 123 Torr and its enthalpy of vaporization is 35.3 kJ mol 1 . Estimate the normal boiling point of methanol. Assume the enthalpy of vaporization is independent of temperature. a). 450 K b). 373 K *c). 342 K d). 315 K e). Not enough information given 4. Calculate the concentration of argon in lake water at 20 ° C. The partial pressure of argon is 6.84 torr and Henry's constant is 0.0015 mol L 1 atm 1 . a). 1.0 × 10 2 M b). 6.0 M c). 9.0 × 10 3 M d). 0.17 M *e). 1.4 × 10 5 M 5. Calculate the total vapor pressure at 25 ° C of a mixture of benzene and toluene in which the mole fraction of benzene is 0.650. The vapor pressure at 25 ° C of benzene is 94.6 Torr and that of toluene is 29.1 Torr. a) 84.4 Torr b) 124 Torr c) 51.3 Torr *d) 71.7 Torr e) 61.5 Torr
Background image of page 1

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

View Full Document Right Arrow Icon
Chem 6B Practice Exam 2A 2 - A Prof. Crowell 6. For CaCl 2 , the absolute value of the enthalpy of hydration is larger than the absolute value of the lattice enthalpy. This means that for CaCl 2 a). the lattice enthalpy is negative. b). the enthalpy of solution is endothermic. *c). the enthalpy of solution is exothermic. d). the enthalpy of hydration is positive.
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.

{[ snackBarMessage ]}

Page1 / 4

Chem Practice Exam 2-1 Answers - CHEM 6B PRACTICE EXAM...

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