August 2006 Chemistry Regents #31-40

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

 

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31 What is the mass number of an atom that has six protons, six electrons, and eight neutrons?
(1) 6     (3) 14
(2) 12   (4) 20
3 6 protons =atomic # 6
2 mass# of 27= 13p+ and 14no
4 an electron mass is approximately 1/1836 of a proton, so the proton is about 2000x more massive
34 Based on electronegativity values, which type of elements tends to have the greatest attraction for electrons in a bond?
(1) metals        (3) nonmetals
(2) metalloids   (4) noble gases
3 fluorine is the greatest, it is a nonmetal
35 Which list of elements from Group 2 on the Periodic Table is arranged in order of increasing  atomic radius?
(1) Be, Mg, Ca      (3) Ba, Ra, Sr
(2) Ca, Mg, Be      (4) Sr, Ra, Ba
1 Table S has the values, put them in order
36 Which half-reaction shows conservation of charge?
(1) Cu + e- --> Cu+        (3) Cu+ --> Cu + e-
(2) Cu2+ + 2e- --> Cu    (4) Cu2+ -->Cu + 2e-
2 The total charge on the left must equal the total charge on the right
1 plug in mass of MG and divide by total x100%
38 Given the balanced equation:
CaCO3(s) + 2HCl(aq) -->CaCl2(aq) + H2O(l) + CO2(g)
What is the total number of moles of CO2 formed when 20. moles of HCl is completely consumed?
(1) 5.0 mol     (3) 20. mol
(2) 10. mol     (4) 40. mol
2 set up a proportion

20/2 =x/1

39 What amount of heat is required to completely melt a 29.95-gram sample of H2O(s) at 0C?
(1) 334 J      (3) 1.00 103 J
(2) 2260 J    (4) 1.00 104 J
4 melt (fusion)

q=mHf= 29.95 x 334

4 elements are not attached

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

 
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