January 2017 Chemistry Regents #66-68

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Question 51-53 Questions 54-55
 Questions 56-57 Questions 58-59 Questions 60-61 Questions 62-65  Questions 66-68  Questions 69-72  Questions 73-77 Questions 78-79 Questions 80-82 Questions 83-85
 

 

 

 

 

 #66-68
  

Carbon dioxide, CO2, changes from the solid phase to the gas phase at 1 atm and 194.5 K. In the solid phase, CO2 is often called dry ice. When dry ice sublimes in air at 298 K, the water vapor in the air can condense, forming a fog of small water droplets. This fog is often used for special effects at concerts and in movie-making.

66 State the direction of heat flow between the dry ice and the water vapor in the air. [1]

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water to dry ice

67 At 1 atm and 298 K, compare the potential energies of the water molecules before and after the water vapor condenses. [1]

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water vapor has a higher PE

 68 At 1 atm and 190. K, compare the amount of thermal energy in a 1.0-kilogram block of dry ice to the amount of thermal energy in a 2.0-kilogram block of dry ice. [1]

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2.0kg block has more thermal energy
  

on to Questions 69-72

  

Questions 1-5 Questions 6-10 Questions 11-15 Questions 16-20 Questions 21-25 Questions 26-30 Questions 31-35 Questions 36-40 Questions 41-45 Questions 46-50

Question 51-53 Questions 54-55
 Questions 56-57 Questions 58-59 Questions 60-61 Questions 62-65  Questions 66-68  Questions 69-72  Questions 73-77 Questions 78-79 Questions 80-82 Questions 83-85