August 2005 Chemistry Regents #21-30

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

Other Regents Exams

Questions	Answer	Explanations
21 Given the reaction system in a closed container at equilibrium and at a temperature of 298 K: N2O4(g) <==>2NO2(g) The measurable quantities of the gases at equilibrium must be (1) decreasing    (3) equal (2) increasing     (4) constant	4	concentrations are constant and rates are equal
22 Atoms of which element can bond with each other to form ring and chain structures in compounds? (1) C     (3) H (2) Ca   (4) Na	1	organic chem. question...carbon
23 In a voltaic cell, chemical energy is converted to (1) electrical energy, spontaneously (2) electrical energy, nonspontaneously (3) nuclear energy, spontaneously (4) nuclear energy, nonspontaneously	1	see answer
	4	highest temp and concentration
25 Which aqueous solution is the best conductor of an electrical current? (1) 0.01 M CH3OH (3) 0.1 M CH3OH (2) 0.01 M KOH (4) 0.1 M KOH	4	highest Molarity and acid, base or salt
26 A hydrogen ion, H+, in aqueous solution may also be written as (1) H2O         (3) H3O+ (2) H2O2         (4) OH–	3	H+ = H3O+
27 One acid-base theory states that an acid is (1) an electron donor    (3) an H+ donor (2) a neutron donor     (4) an OH– donor	3	acids=H+ donor bases= H+ acceptor
28 Which isotope will spontaneously decay and emit particles with a charge of +2? (1) 53Fe      (3) 198Au (2) 137Cs    (4) 220Fr	4	table N
29 Radioactive cobalt-60 is used in radiation therapy treatment. Cobalt-60 undergoes beta decay. This type of nuclear reaction is called (1) natural transmutation (2) artificial transmutation (3) nuclear fusion (4) nuclear fission	1	nothing else is needed=natural
30 Given the balanced ionic equation: 2Al(s) + 3Cu2+(aq)==> 2Al3+(aq) + 3Cu(s) Compared to the total charge of the reactants, the total charge of the products is (1) less (2) greater (3) the same	3	the same, charge is conserved