Regents Chemistry Exam Explanations June 2009

June 2009 Chemistry Regents #11-20

Highlight to reveal answers and explanations

Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50
Questions 51-53 Questions 54-57 Questions 58-59 Questions 60-62 Questions 63-65 Questions 66-67 Questions 68-70 Questions 71-73 Questions 74-76 Questions 77-78 Questions 79-83

Questions
Answer Explanations
11 The compound XCl is classified as ionic if X represents the element
(1) H      (3) Rb
(2) I       (4) Br 3 has a 1+ charge, Group 1
12 The chemical bonding in sodium phosphate, Na₃PO₄, is classified as
(1) ionic, only
(2) metallic, only
(3) both covalent and ionic
(4) both covalent and metallic 3 3 elements bonded and one is a metal
both Ionic and Covalent
13 Which element is composed of molecules that each contain a multiple covalent bond?
(1) chlorine     (3) hydrogen
(2) fluorine      (4) nitrogen 4 nitrogen bonds 3 times
the others only bond once
2 Use TABLE I
negative DH is exothermic
15 Standard pressure is equal to
(1) 1 atm        (3) 273 atm
(2) 1 kPa        (4) 273 kPa 1 see TABLE A
16 A large sample of solid calcium sulfate is crushed into smaller pieces for testing. Which two physical properties are the same for both the large sample and one of the smaller pieces?
(1) mass and density
(2) mass and volume
(3) solubility and density
(4) solubility and volume 3 properties that will not change
17 According to the kinetic molecular theory, the molecules of an ideal gas
(1) have a strong attraction for each other
(2) have significant volume
(3) move in random, constant, straight-line motion
(4) are closely packed in a regular repeating pattern 3 Rules of an Ideal Gas
random, straight-line motion
no attractions
18 At 65°C, which compound has a vapor pressure of 58 kilopascals?
(1) ethanoic acid     (3) propanone
(2) ethanol              (4) water 2 use TABLE H
19 At STP, which 2.0-gram sample of matter uniformly fills a 340-milliliter closed container?
(1) Br_2(l)(3) KCl_(aq)
(2) Fe(NO₃)_2(s) (4) Xe_(g) 4 Gas ==>uniformly fills
20 Compared to the freezing point and boiling point of water at 1 atmosphere, a solution of a salt and water at 1 atmosphere has a
(1) lower freezing point and a lower boiling point
(2) lower freezing point and a higher boiling point
(3) higher freezing point and a lower boiling point
(4) higher freezing point and a higher boiling point
2 BP increase
FP decrease
Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50
Questions 51-53 Questions 54-57 Questions 58-59 Questions 60-62 Questions 63-65 Questions 66-67 Questions 68-70 Questions 71-73 Questions 74-76 Questions 77-78 Questions 79-83

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Questions	Answer	Explanations
11 The compound XCl is classified as ionic if X represents the element (1) H (3) Rb (2) I (4) Br	3	has a 1+ charge, Group 1
12 The chemical bonding in sodium phosphate, Na₃PO₄, is classified as (1) ionic, only (2) metallic, only (3) both covalent and ionic (4) both covalent and metallic	3	3 elements bonded and one is a metal both Ionic and Covalent
13 Which element is composed of molecules that each contain a multiple covalent bond? (1) chlorine (3) hydrogen (2) fluorine (4) nitrogen	4	nitrogen bonds 3 times the others only bond once
	2	Use TABLE I negative DH is exothermic
15 Standard pressure is equal to (1) 1 atm (3) 273 atm (2) 1 kPa (4) 273 kPa	1	see TABLE A
16 A large sample of solid calcium sulfate is crushed into smaller pieces for testing. Which two physical properties are the same for both the large sample and one of the smaller pieces? (1) mass and density (2) mass and volume (3) solubility and density (4) solubility and volume	3	properties that will not change
17 According to the kinetic molecular theory, the molecules of an ideal gas (1) have a strong attraction for each other (2) have significant volume (3) move in random, constant, straight-line motion (4) are closely packed in a regular repeating pattern	3	Rules of an Ideal Gas random, straight-line motion no attractions
18 At 65°C, which compound has a vapor pressure of 58 kilopascals? (1) ethanoic acid (3) propanone (2) ethanol (4) water	2	use TABLE H
19 At STP, which 2.0-gram sample of matter uniformly fills a 340-milliliter closed container? (1) Br_2(l)(3) KCl_(aq) (2) Fe(NO₃)_2(s) (4) Xe_(g)	4	Gas ==>uniformly fills
20 Compared to the freezing point and boiling point of water at 1 atmosphere, a solution of a salt and water at 1 atmosphere has a (1) lower freezing point and a lower boiling point (2) lower freezing point and a higher boiling point (3) higher freezing point and a lower boiling point (4) higher freezing point and a higher boiling point	2	BP increase FP decrease