January 2009 Chemistry Regents #31-40

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

Questions 51-53 Questions 54-55 Questions 56-58 Questions 59-61 Questions 62-64 Questions 65-66 Questions 67-68 Questions 69-71 Questions 72-74 Questions 75-77 Questions 78-79 Questions 80-81

 

Other Regents Exams

Questions

Answer Explanations
2 match up the lines
2 protons determine the element
33 What is the total number of valence electrons in an atom of germanium in the ground state?
(1) 8    (3) 14
(2) 2    (4) 4
4 Ge outer electron shell

2-8-18-4

34 In the formula X2O5, the symbol X could represent an element in Group
(1) 1    (3) 15
(2) 2    (4) 18
3 charge of X =+5  group 15
35 A 50.0-gram block of copper at 10.0C is carefully lowered into 100.0 grams of water at 90.0C in an insulated container. Which statement describes the transfer of heat in this system?
(1) The water loses heat to the block until both are at 10.0C.
(2) The block gains heat from the water until both are at 90.0C.
(3) The water loses heat and the block gains heat until both are at the same temperature that is between 10.0C and 90.0C.
(4) The water gains heat and the block loses heat until both are at the same temperature that is between 10.0C and 90.0C.
3 heat flows from hot to cold and the temperature of both end up between the two
36 The compounds C2H4 and C4H8 have the same
(1) freezing point at standard pressure
(2) boiling point at standard pressure
(3) molecular formula
(4) empirical formula
4 they reduce to CH2
37 The chemical bond between which two atoms is most polar?
(1) CN    (3) SCl
(2) HH    (4) SiO
4 look up their electronegativities. The biggest difference.
38 What is the total amount of heat absorbed by 100.0 grams of water when the temperature of the water is increased from 30.0C to 45.0C?
(1) 418 J      (3) 12 500 J
(2) 6270 J    (4) 18 800 J
2 q=mc delta T= 100g x 4.18 x 15C
39 Which process is exothermic?
(1) boiling of water
(2) melting of copper
(3) condensation of ethanol vapor
(4) sublimation of iodine
3 SLG problem

g-->L

40 Which sample, when dissolved in 1.0 liter of water, produces a solution with the lowest freezing point?
(1) 0.1 mol of C2H5OH
(2) 0.1 mol of LiBr
(3) 0.2 mol of C6H12O6
(4) 0.2 mol of CaCl2
4 the most concentrated solution based on the ions

0.2m CaCl2 has 0.6 mol of ions

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

Questions 51-53 Questions 54-55 Questions 56-58 Questions 59-61 Questions 62-64 Questions 65-66 Questions 67-68 Questions 69-71 Questions 72-74 Questions 75-77 Questions 78-79 Questions 80-81

 
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