August 2008 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
	2	Longest chain 5 carbons single bonded=  pentane 1 carbon side chain= methyl
22 A voltaic cell spontaneously converts chemical energy to (1) electrical energy      (3) mechanical energy (2) geothermal energy  (4) nuclear energy	1	voltaic cells are batteries
23 Given the balanced equation representing a reaction: Mg(s) + Ni2+(aq) ==> Mg2+(aq) + Ni(s) What is the total number of moles of electrons lost by Mg(s) when 2.0 moles of electrons are gained by Ni2+(aq)? (1) 1.0 mol   (3) 3.0 mol (2) 2.0 mol    (4) 4.0 mol	2	moles of electrons lost=moles of electrons gained
24 Which half-reaction correctly represents reduction? (1) Mn4+ ==> Mn3+ + e- (2) Mn4+ ==>Mn7+ + 3e- (3) Mn4+ + e- ==>Mn3+ (4) Mn4+ + 3e- ==> Mn7+	3	charge goes down and electrons go on the more positive side
25 Which indicator is blue in a solution that has a pH of 5.6? (1) bromcresol green   (3) methyl orange (2) bromthymol blue    (4) thymol blue	1	Table M
26 The Arrhenius theory explains the behavior of (1) acids and bases (2) alcohols and amines (3) isomers and isotopes (4) metals and nonmetals	1	Arrhenius acid base theory (25-27 are acid base questions)
27 In which laboratory process could a student use 0.10 M NaOH(aq) to determine the concentration of an aqueous solution of HBr? (1) chromatography (2) decomposition of the solute (3) evaporation of the solvent (4) titration	4	Titrations Definition
28 A nuclear reaction in which two light nuclei combine to form a more massive nucleus is called (1) addition    (3) fusion (2) fission       (4) substitution	3	definition of Fusion
29 The nucleus of a radium-226 atom is unstable, which causes the nucleus to spontaneously (1) absorb electrons   (3) decay (2) absorb protons     (4) oxidize	3	radioactive nuclei will decay
30 A serious risk factor associated with the operation of a nuclear power plant is the production of (1) acid rain (2) helium gas (3) greenhouse gases, such as CO2 (4) radioisotopes with long half-lives	4	pick the bad one, that has to do with radiation