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The University of the State of New York
REGENTS HIGH SCHOOL EXAMINATION
PHYSICAL SETTING
CHEMISTRY
Tuesday, June 23, 2015 — 9:15 a.m. to 12:15 p.m., only
This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the 2011 Edition Reference Tables for Physical Setting/Chemistry****. You are to answer all questions in all parts of this examination according to the directions provided in this examination booklet.
A separate answer sheet for Part A and Part B–1 has been provided to you. Follow the instructions from the proctor for completing the student information on your answer sheet. Record your answers to the Part A and Part B–1 multiple-choice questions on this separate answer sheet. Record your answers for the questions in Part B–2 and Part C in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet.
All answers in your answer booklet should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet or in your answer booklet as directed.
When you have completed the examination, you must sign the statement printed on your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration.
DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN.
The possession or use of any communications device is strictly prohibited when taking this examination. If you have or use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you.
Notice... A four-function or scientific calculator and a copy of the 2011 Edition Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination.
P.S./CHEMISTRY
P.S./CHEMISTRY
Part A
Answer all questions in this part.
Directions (1–30): For each statement or question, record on your separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the 2011 Edition Reference Tables for Physical Setting / Chemistry.
P.S./Chem.–June ’15 [2]
1 Compared to an electron, which particle has a charge that is equal in magnitude but opposite in sign? (1) an alpha particle (3) a neutron (2) a beta particle (4) a proton
2 The mass of a proton is approximately equal to (1) 1 atomic mass unit (2) 12 atomic mass units (3) the mass of 1 mole of carbon atoms (4) the mass of 12 moles of electrons
3 Which property decreases when the elements in Group 17 are considered in order of increasing atomic number? (1) atomic mass (3) melting point (2) atomic radius (4) electronegativity
4 Any substance composed of two or more elements that are chemically combined in a fixed proportion is (1) an isomer (3) a solution (2) an isotope (4) a compound
5 Which term refers to how strongly an atom of an element attracts electrons in a chemical bond with an atom of a different element? (1) entropy (2) electronegativity (3) activation energy (4) first ionization energy
6 At STP, which substance has metallic bonding? (1) ammonium chloride (3) iodine (2) barium oxide (4) silver
7 What is the number of electrons shared between the carbon atoms in a molecule of ethyne? (1) 6 (3) 8 (2) 2 (4) 4
8 Which atom in the ground state has a stable valence electron configuration? (1) Ar (3) Si (2) Al (4) Na
9 What occurs when two fluorine atoms react to produce a fluorine molecule? (1) Energy is absorbed as a bond is broken. (2) Energy is absorbed as a bond is formed. (3) Energy is released as a bond is broken. (4) Energy is released as a bond is formed.
10 Which gas sample at STP has the same number of molecules as a 2.0-liter sample of Cl 2 (g) at STP? (1) 1.0 L of NH 3 (g) (3) 3.0 L of CO 2 (g) (2) 2.0 L of CH 4 (g) (4) 4.0 L of NO(g)
11 All atoms of uranium have the same (1) mass number (2) atomic number (3) number of neutrons plus protons (4) number of neutrons plus electrons
12 The concentration of a solution can be expressed in (1) kelvins (2) milliliters (3) joules per kilogram (4) moles per liter
P.S./Chem.–June ’15 [4]
26 Given the equation representing a system at equilibrium:
N 2 (g) 3H 2 (g) 2NH 3 (g)
Which statement describes this reaction at equilibrium? (1) The concentration of N 2 (g) decreases. (2) The concentration of N 2 (g) is constant. (3) The rate of the reverse reaction decreases. (4) The rate of the reverse reaction increases.
27 The acidity or alkalinity of an unknown aqueous solution is indicated by its (1) pH value (2) electronegativity value (3) percent by mass concentration (4) percent by volume concentration
28 The laboratory process in which the volume of a solution of known concentration is used to determine the concentration of another solution is called (1) distillation (3) titration (2) fermentation (4) transmutation
29 Which list of nuclear emissions is arranged in order from the greatest penetrating power to the least penetrating power? (1) alpha particle, beta particle, gamma ray (2) alpha particle, gamma ray, beta particle (3) gamma ray, alpha particle, beta particle (4) gamma ray, beta particle, alpha particle
30 Given the diagram representing a reaction:
Which type of change is represented? (1) fission (3) deposition (2) fusion (4) evaporation
94
38 Sr^
140
54 Xe
1
0 n
235
92 U
1
0 n^
1
0 n
31 Which electron shell contains the valence electrons of a radium atom in the ground state? (1) the sixth shell (3) the seventh shell (2) the second shell (4) the eighteenth shell
32 Each diagram below represents the nucleus of an atom.
How many different elements are represented by the diagrams? (1) 1 (3) 3 (2) 2 (4) 4
33 Chlorine and element X have similar chemical properties. An atom of element X could have an electron configuration of (1) 2-2 (3) 2-8- (2) 2-8-1 (4) 2-8-18-
34 Which group of elements contains a metalloid? (1) Group 8 (3) Group 16 (2) Group 2 (4) Group 18
35 Which Lewis electron-dot diagram represents a fluoride ion?
36 In the formula for the compound X Cl 4 , the X could represent (1) C (3) Mg (2) H (4) Zn
37 The formula C 2 H 4 can be classified as (1) a structural formula, only (2) a molecular formula, only (3) both a structural formula and an empirical formula (4) both a molecular formula and an empirical formula
38 Given the balanced equation representing a reaction:
4Al(s) + 3O 2 (g) → 2Al 2 O 3 (s)
How many moles of Al(s) react completely with 4.50 moles of O 2 (g) to produce 3.00 moles of Al 2 O 3 (s)? (1) 1.50 mol (3) 6.00 mol (2) 2.00 mol (4) 4.00 mol
39 What is the percent composition by mass of oxygen in Ca(NO 3 ) 2 (gram-formula mass = 164 g/mol)? (1) 9.8% (3) 48% (2) 29% (4) 59%
F F F
F
( 1 ) ( 2 ) ( 3 ) ( 4 )
1p
0n
1p
1n
2p
1n
2p
2n
P.S./Chem.–June ’15 [5] [OVER]
Part B–
Answer all questions in this part.
Directions (31–50): For each statement or question, record on your separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the 2011 Edition Reference Tables for Physical Setting / Chemistry.
P.S./Chem.–June ’15 [7] [OVER]
Base your answers to questions 48 and 49 on the graph below and on your knowledge of chemistry.
48 What is represented by the number “1” in the IUPAC name for three of these alcohols? (1) the number of isomers for each alcohol (2) the number of OH groups for each carbon atom in each alcohol molecule (3) the location of an OH group on one end of the carbon chain in each alcohol molecule (4) the location of an OH group in the middle of the carbon chain in each alcohol molecule
49 What can be concluded from this graph? (1) At 101.3 kPa, water has a higher boiling point than 1-butanol. (2) At 101.3 kPa, water has a lower boiling point than ethanol. (3) The greater the number of carbon atoms per alcohol molecule, the lower the boiling point of the alcohol. (4) The greater the number of carbon atoms per alcohol molecule, the higher the boiling point of the alcohol.
150
125
100
75
(^50) methanol ethanol 1-propanol 1-butanol 1-pentanol
Boiling Points of Selected Alcohols at 101.3 kPa
Alcohol
50 In the laboratory, a student investigates the effect of concentration on the reaction between HCl(aq) and Mg(s), changing only the concentration of HCl(aq). Data for two trials in the investigation are shown in the table below.
Data Table
Compared to trial 1, what is the expected reaction time for trial 2 and the explanation for that result? (1) less than 48 s, because there are fewer effective particle collisions per second (2) less than 48 s, because there are more effective particle collisions per second (3) more than 48 s, because there are fewer effective particle collisions per second (4) more than 48 s, because there are more effective particle collisions per second
Trial Volume of HCl(aq) (mL)
Concentration of HCl(aq) (M)
Mass of Mg(s) (g)
Reaction Time (s) 1 50.0 0.2 0.1 48 2 50.0 0.4 0.1?
P.S./Chem.–June ’15 [8]
P.S./Chem.–June ’15 [10]
Base your answers to questions 57 through 59 on the information below and on your knowledge of chemistry.
The equation below represents an equilibrium system of SO 2 (g), O 2 (g), and SO 3 (g). The reaction can be catalyzed by vanadium or platinum.
2SO 2 (g) O 2 (g) 2SO 3 (g) energy
57 Compare the rates of the forward and reverse reactions at equilibrium. [ 1]
58 State how the equilibrium shifts when SO 3 (g) is removed from the system. [1]
59 A potential energy diagram for the forward reaction is shown in your answer booklet. On this diagram, draw a dashed line to show how the potential energy changes when the reaction occurs by the catalyzed pathway. [1]
Base your answers to questions 60 and 61 on the information below and on your knowledge of chemistry.
The formulas for two compounds are shown below.
60 Explain, in terms of bonding, why compound A is saturated. [ 1 ]
61 Explain, in terms of molecular structure, why the chemical properties of compound A are different from the chemical properties of compound B. [1]
H
H C
H
C C
H
H
H
H
H
C
H
C C
H
H
H
H
H
H
H C
H
C C
H
H
H
H
H
C
H
C C
H
H
O
OH
Compound A Compound B
P.S./Chem.–June ’15 [11] [OVER]
Base your answers to questions 62 through 65 on the information below and on your knowledge of chemistry.
Some isotopes of potassium are K-37, K-39, K-40, K-41, and K-42. The natural abundance and the atomic mass for the naturally occurring isotopes of potassium are shown in the table below.
Naturally Occurring Isotopes of Potassium
62 Identify the decay mode of K-37. [ 1]
63 Complete the nuclear equation in your answer booklet for the decay of K-40 by writing a notation for the missing nuclide. [1]
64 Determine the fraction of an original sample of K-42 that remains unchanged after 24.72 hours. [1]
65 Show a numerical setup for calculating the atomic mass of potassium. [1]
Isotope Notation
Natural Abundance (%)
Atomic Mass (u) K-39 93.26 38. K-40 0.01 39. K-41 6.73 40.
P.S./Chem.–June ’15 [13] [OVER]
Base your answers to questions 69 through 72 on the information below and on your knowledge of chemistry.
In 1828, Friedrich Wöhler produced urea when he heated a solution of ammonium cyanate. This reaction is represented by the balanced equation below.
69 Identify the element in urea that makes it an organic compound. [1]
70 Determine the gram-formula mass of the product. [ 1]
71 Write an empirical formula for the product. [1]
72 Explain why this balanced equation represents a conservation of atoms. [1]
Base your answers to questions 73 through 75 on the information below and on your knowledge of chemistry.
Rubbing alcohol sold in stores is aqueous 2-propanol, CH 3 CHOHCH 3 (aq). Rubbing alcohol is available in concentrations of 70.% and 91% 2-propanol by volume. To make 100. mL of 70.% aqueous 2-propanol, 70. mL of 2-propanol is diluted with enough water to produce a total volume of 100. mL. In a laboratory investigation, a student is given a 132-mL sample of 91% aqueous 2-propanol to separate using the process of distillation.
73 State evidence that indicates the proportions of the components in rubbing alcohol can vary. [ 1]
74 Identify the property of the components that makes it possible to use distillation to separate the 2-propanol from water. [ 1]
75 Determine the maximum volume of 2-propanol in the 132-mL sample. [ 1]
H N H
H
H
C N O −^ N
H
H
C N
H
H
O
Ammonium cyanate
Urea
P.S./Chem.–June ’15 [14]
Base your answers to questions 76 through 79 on the information below and on your knowledge of chemistry.
A sample of seawater is analyzed. The table below gives the concentration of some ions in the sample. Concentration of Some Ions in a Seawater Sample
76 Write a chemical formula of one compound formed by the combination of K^ ions with one of these ions as water completely evaporates from the seawater sample. [1]
77 Determine the number of moles of the SO 42 ^ ion in a 1400.-liter sample of the seawater. [1]
78 Compare the radius of an Mg^2 ^ ion in the seawater to the radius of an Mg atom. [1]
79 Using the key in your answer booklet , draw two water molecules in the box, showing the orientation of each water molecule toward the calcium ion. [1]
Base your answers to questions 80 through 82 on the information below and on your knowledge of chemistry.
A scientist bubbled HCl(g) through a sample of H 2 O(ℓ). This process is represented by the balanced equation below.
H 2 O(ℓ) + HCl(g) → H 3 O(aq) + Cl(aq)
The scientist measured the pH of the liquid in the flask before and after the gas was bubbled through the water. The initial pH value of the water was 7.0 and the final pH value of the solution was 3.0.
80 Explain, in terms of ions, why the gaseous reactant in the equation is classified as an Arrhenius acid. [1]
81 What would be the color of bromcresol green if it had been added to the water in the flask before any of the HCl(g) was bubbled through the water? [1]
82 Compare the hydronium ion concentration of the solution that has the pH value of 3. to the hydronium ion concentration of the water. [1]
Ion Concentration (M)
Cl–^ 0. Na+^ 0. Mg2+^ 0. SO 4 2–^ 0.
Ca2+^ 0. K+^ 0.
P.S./CHEMISTRY
P.S./CHEMISTRY
Printed on Recycled Paper
The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION
PHYSICAL SETTING
CHEMISTRY
Tuesday, June 23, 2015 — 9:15 a.m. to 12:15 p.m., only
ANSWER BOOKLET
Student.......................................................................... Sex: Female
Teacher..........................................................................
School........................................................................... Grade.........
Record your answers for Part B–2 and Part C in this booklet.
Male
51 mL
52 g
Part B–
63^4019 K → (^) ^01 e
P.S./Chem. Answer Booklet–June ’15 [3] [OVER]
66 Atomic number:
Mass number:
67 Number of electrons in first shell:
Number of electrons in second shell:
68 Change in electron energy:
Change in electron location:
70 g/mol
P.S./Chem. Answer Booklet–June ’15 [4]
Part C
