January 2010 Chemistry Regents #41-50

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Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50

Questions 51-52 Questions 53-55 Questions 56-57 Questions 58-60 Questions 61-63 Questions 64-65 Questions 66-68 Questions 69-71 Questions 72-75 Questions 76-78 Questions 79-81  Questions 82-84

 

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Questions

AnswerLinkExplanations
41 What occurs when a 35-gram aluminum cube at 100.°C is placed in 90. grams of water at 25°C in an insulated cup?
(1) Heat is transferred from the aluminum to the water, and the temperature of the water decreases.
(2) Heat is transferred from the aluminum to the water, and the temperature of the water increases.
(3) Heat is transferred from the water to the aluminum, and the temperature of the water decreases.
(4) Heat is transferred from the water to the aluminum, and the temperature of the water increases.		2LinkHeat flows from hot to cold
42 Which temperature is equal to 120. K?
(1) -153°C     (3) +293°C
(2) -120.°C    (4) +393°C		1LinkC=K+ 273

Table T

43 A rigid cylinder contains a sample of gas at STP. What is the pressure of this gas after the sample is heated to 410 K?
(1) 1.0 atm      (3) 0.67 atm
(2) 0.50 atm    (4) 1.5 atm		4LinkP/T =P/T 

1atm/273K =P/410K

44 Given the balanced equation representing a phase change:
C6H4Cl2(s) + energy==>C6H4Cl2(g)
Which statement describes this change?
(1) It is endothermic, and entropy decreases.
(2) It is endothermic, and entropy increases.
(3) It is exothermic, and entropy decreases.
(4) It is exothermic, and entropy increases.		2LinkA

LinkB

endothermic energy is on the left

S--> G increase in entropy

45 In a biochemical reaction, an enzyme acts as a catalyst, causing the
(1) activation energy of the reaction to decrease
(2) potential energy of the reactants to decrease
(3) kinetic energy of the reactants to increase
(4) heat of reaction to increase		1Linkcatalyst lowers activation energy
4LinkTable R
47 Butanal and butanone have different chemical and physical properties primarily because of differences in their
(1) functional groups
(2) molecular masses
(3) molecular formulas
(4) number of carbon atoms per molecule		1LinkA

LinkB

aldehydes and ketones have different functional groups
48 Which salt is produced when sulfuric acid and calcium hydroxide react completely?
(1) CaH2 (3) CaS
(2) CaO (4) CaSO4		4Linkcalcium sulfate
49 Which radioisotope is used to treat thyroid disorders?
(1) Co-60 (3) C-14
(2) I-131 (4) U-238		2Linkthyroid = iodine
4LinkUse Table S Higher to lower, or Zn to Ni, lose to gain

 

through the wire

Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50

Questions 51-52 Questions 53-55 Questions 56-57 Questions 58-60 Questions 61-63 Questions 64-65 Questions 66-68 Questions 69-71 Questions 72-75 Questions 76-78 Questions 79-81  Questions 82-84

 
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