June 2007 Chemistry Regents #41-50

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



Answer Explanations
41 At STP, fluorine is a gas and bromine is a liquid because, compared to fluorine, bromine has
(1) stronger covalent bonds
(2) stronger intermolecular forces
(3) weaker covalent bonds
(4) weaker intermolecular forces
2 Liquids have stronger IMF's compared to gases
42 The boiling point of a liquid is the temperature at which the vapor pressure of the liquid is equal to the pressure on the surface of the liquid. What is the boiling point of propanone if the pressure on its surface is 48 kilopascals?
(1) 25C    (3) 35C
(2) 30.C   (4) 40.C
3 Table H
43 At which Celsius temperature does lead change
from a solid to a liquid?
(1) 874C    (3) 328C
(2) 601C    (4) 0C
3 Melting points Table S
44 Given the equation representing a reaction at equilibrium:
N2(g) + 3H2(g)==> 2NH3(g) + energy
Which change causes the equilibrium to shift to the right?
(1) decreasing the concentration of H2(g)
(2) decreasing the pressure
(3) increasing the concentration of N2(g)
(4) increasing the temperature

Pressure forces a shift to the side with the lower moles of gases

45 Which compound is an unsaturated hydrocarbon?
(1) hexanal    (3) hexanoic acid
(2) hexane     (4) hexyne
4 Unsaturated -double or triple bonded

hydrocarbon hydrogen and carbon only

Table Q

46 The organic compound represented by the condensed structural formula CH3CH2CH2CHO
is classified as an
(1) alcohol      (3) ester
(2) aldehyde   (4) ether
2 CH=O aldehyde
47 Given the balanced ionic equation representing a reaction:
2Al3+(aq) + 3Mg(s)==>3Mg2+(aq) + 2Al(s)
In this reaction, electrons are transferred from
(1) Al to Mg2+    (3) Mg to Al3+
(2) Al3+ to Mg   (4) Mg2+ to Al
3 lose to gain

ox. to red


48 Which two formulas represent Arrhenius acids?
(1) CH3COOH and CH3CH2OH
(2) HC2H3O2 and H3PO4
(3) KHCO3 and KHSO4
(4) NaSCN and Na2S2O3
2 Table K
3 MV=MV but because H2SO2 has 2 H's

it is MV=2MV


50 Which radioisotope is used in medicine to treat thyroid disorders?
(1) cobalt-60      (3) phosphorus-32
(2) iodine-131     (4) uranium-238
2 thyroid- iodide

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

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