Syvum Home Page

Home > Examinations > NYSED Regents Exams > Chemistry > Print Preview

Physical Setting / Chemistry - New York Regents June 2014 Exam

Formats Worksheet / Test Paper Quiz Review

Hide all answers   View all answers   Print   Try the Quiz

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.

1.
1 Compared to the charge of a proton, the charge
  of an electron has
  (1) a greater magnitude and the same sign
  (2) a greater magnitude and the opposite sign
  (3) the same magnitude and the same sign
  (4) the same magnitude and the opposite sign
Answer: 4

2.
2 Which atom has the largest atomic radius?
  (1) potassium           (3) francium
  (2) rubidium            (4) cesium
Answer: 3

3.
3 In the wave-mechanical model of the atom, an
  orbital is defined as
  (1) a region of the most probable proton location
  (2) a region of the most probable electron
      location
  (3) a circular path traveled by a proton around
      the nucleus
  (4) a circular path traveled by an electron
      around the nucleus
Answer: 2


4.
4 When an excited electron in an atom moves to
  the ground state, the electron
  (1) absorbs energy as it moves to a higher
      energy state
  (2) absorbs energy as it moves to a lower energy
      state
  (3) emits energy as it moves to a higher energy
      state
  (4) emits energy as it moves to a lower energy
      state
Answer: 4

5.
5 Which polyatomic ion is found in the compound
  represented by the formula NaHCO3?
  (1) acetate              (3) hydrogen sulfate
  (2) hydrogen carbonate (4) oxalate
Answer: 2

6.
6 The atomic mass of magnesium is the weighted
  average of the atomic masses of
  (1) all of the artificially produced isotopes of Mg
  (2) all of the naturally occurring isotopes of Mg
  (3) the two most abundant artificially produced
      isotopes of Mg
  (4) the two most abundant naturally occurring
      isotopes of Mg
Answer: 2

7.
7 Which element has atoms that can form halide
  ions?
  (1) iodine            (3) strontium
  (2) silver            (4) xenon
Answer: 1

8.
8 Two forms of solid carbon, diamond and
  graphite, differ in their physical properties due
  to the differences in their
  (1) atomic numbers
  (2) crystal structures
  (3) isotopic abundances
  (4) percent compositions
Answer: 2

9.
9 Which quantity can be calculated for a solid
  compound, given only the formula of the com-
  pound and the Periodic Table of the Elements?
  (1) the density of the compound
  (2) the heat of fusion of the compound
  (3) the melting point of each element in the
      compound
  (4) the percent composition by mass of each
      element in the compound
Answer: 4

10.
10 Which terms identify types of chemical
   reactions?
   (1) decomposition and sublimation
   (2) decomposition and synthesis
   (3) deposition and sublimation
   (4) deposition and synthesis
Answer: 2

11.
11 The greatest amount of energy released per
   gram of reactants occurs during a
   (1) redox reaction
   (2) fission reaction
   (3) substitution reaction
   (4) neutralization reaction
Answer: 2

12.
12 Which element has atoms with the strongest
   attraction for electrons in a chemical bond?
   (1) chlorine               (3) fluorine
   (2) nitrogen               (4) oxygen
Answer: 3

13.
13 Compared to the physical and chemical proper-
   ties of the compound NO2, the compound N2O
   has
   (1) different physical properties and different
       chemical properties
   (2) different physical properties and the same
       chemical properties
   (3) the same physical properties and different
       chemical properties
   (4) the same physical properties and the same
       chemical properties
Answer: 1

14.
14 Which phrase describes a molecule of CH4, in
   terms of molecular polarity and distribution of
   charge?
   (1) polar with an asymmetrical distribution of
       charge
   (2) polar with a symmetrical distribution of
       charge
   (3) nonpolar with an asymmetrical distribution
       of charge
   (4) nonpolar with a symmetrical distribution of
       charge
Answer: 4

15.
15 Which sample of copper has atoms with the
   lowest average kinetic energy?
   (1) 10. g at 45°C        (3) 30. g at 25°C
   (2) 20. g at 35°C        (4) 40. g at 15°C
Answer: 4

16.
16 Which change results in the formation of
   different substances?
   (1) burning of propane
   (2) melting of NaCl(s)
   (3) deposition of CO2(g)
   (4) solidification of water
Answer: 1

17.
17 Which substance can not be broken down by a
   chemical change?
   (1) ammonia            (3) propanal
   (2) ethanol            (4) zirconium
Answer: 4

18.
18 According to Table I, which equation represents
   a change resulting in the greatest quantity of
   energy released?
   (1) 2C(s) + 3H2(g) → C2H6(g)
   (2) 2C(s) + 2H2(g) → C2H4(g)
   (3) N2(g) + 3H2(g) → 2NH3(g)
   (4) N2(g) + O2(g) → 2NO(g)
Answer: 3

19.
19 Which element is a liquid at STP?
   (1) bromine              (3) francium
   (2) cesium               (4) iodine
Answer: 1

20.
20 Which statement describes a reversible reaction
   at equilibrium?
   (1) The activation energy of the forward
       reaction must equal the activation energy of
       the reverse reaction.
   (2) The rate of the forward reaction must equal
       the rate of the reverse reaction.
   (3) The concentration of the reactants must
       equal the concentration of the products.
   (4) The potential energy of the reactants must
       equal the potential energy of the products.
Answer: 2

21.
21 Given the balanced equation representing a
   reaction:
                  O2 → O + O
   What occurs during this reaction?
   (1) Energy is absorbed as bonds are broken.
   (2) Energy is absorbed as bonds are formed.
   (3) Energy is released as bonds are broken.
   (4) Energy is released as bonds are formed.
Answer: 1

22.
22 In terms of entropy and energy, systems in
   nature tend to undergo changes toward
   (1) lower entropy and lower energy
   (2) lower entropy and higher energy
   (3) higher entropy and lower energy
   (4) higher entropy and higher energy
Answer: 3

23.
23 Which term is defined as the difference
   between the potential energy of the products
   and the potential energy of the reactants in a
   chemical reaction?
   (1) activation energy   (3) heat of fusion
   (2) thermal energy      (4) heat of reaction
Answer: 4

24.
24 What is the atomic number of the element
   whose atoms bond to each other in chains, rings,
   and networks?
   (1) 10                 (3) 6
   (2) 8                  (4) 4
Answer: 3

25.
25 How many pairs of electrons are shared between
   two adjacent carbon atoms in a saturated
   hydrocarbon?
   (1) 1                   (3) 3
   (2) 2                   (4) 4
Answer: 1

26.
26 Given the balanced equation representing a
   reaction:
           4Al(s) + 3O2(g) → 2Al2O3(s)
   As the aluminum loses 12 moles of electrons,
   the oxygen
   (1) gains 4 moles of electrons
   (2) gains 12 moles of electrons
   (3) loses 4 moles of electrons
   (4) loses 12 moles of electrons
Answer: 2

27.
27 Which compound is an electrolyte?
   (1) CH3CHO            (3) CH3COOH
   (2) CH3OCH3           (4) CH3CH2CH3
Answer: 3

28.
28 Which statement describes one acid-base
   theory?
   (1) An acid is an H+ acceptor, and a base is an
       H+ donor.
   (2) An acid is an H+ donor, and a base is an H+
       acceptor.
   (3) An acid is an H- acceptor, and a base is an
       H- donor.
   (4) An acid is an H- donor, and a base is an H-
       acceptor.
Answer: 2

29.
29 Which compounds are classified as Arrhenius
   acids?
   (1) HCl and NaOH
   (2) HNO3 and NaCl
   (3) NH3 and H2CO3
   (4) HBr and H2SO4
Answer: 4

30.
30 Which statement describes the stability of the
   nuclei of potassium atoms?
   (1) All potassium atoms have stable nuclei that
       spontaneously decay.
   (2) All potassium atoms have unstable nuclei
       that do not spontaneously decay.
   (3) Some potassium atoms have unstable nuclei
       that spontaneously decay.
   (4) Some potassium atoms have unstable nuclei
       that do not spontaneously decay.
Answer: 3

31.
31 Which notations represent different isotopes of
   the element sodium?
   (1) 32S and 34S        (3) Na+ and Na0
   (2) S2- and S6+        (4) 22Na and 23Na
Answer: 4

32.
32 Which electron configuration represents the
   electrons in an atom of Ga in an excited state?
   (1) 2-8-17-3             (3) 2-8-18-3
   (2) 2-8-17-4             (4) 2-8-18-4
Answer: 2

33.
33 Which statement describes the general trends in
   electronegativity and first ionization energy as
   the elements in Period 3 are considered in order
   from Na to Cl?
   (1) Electronegativity increases, and first
       ionization energy decreases.
   (2) Electronegativity decreases, and first
       ionization energy increases.
   (3) Electronegativity and first ionization energy
       both increase.
   (4) Electronegativity and first ionization energy
       both decrease.
Answer: 3

34.
34 What is the gram-formula mass of Fe(NO3)3?
   (1) 146 g/mol          (3) 214 g/mol
   (2) 194 g/mol          (4) 242 g/mol
Answer: 4

35.
35 Given the balanced equation representing a
   reaction:
   Al2(SO4)3 + 6NaOH → 2Al(OH)3 + 3Na2SO4
   The mole ratio of NaOH to Al(OH)3 is
   (1) 1:1               (3) 3:1
   (2) 1:3               (4) 3:7
Answer: 3


Part B–1
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.

36.
36 Which equation represents a single replacement
   reaction?
   (1) 2H2O2 → 2H2O + O2
   (2) 2H2 + O2 → 2H2O
   (3) H2SO4 + Mg → H2 + MgSO4
   (4) HCl + KOH → KCl + H2O
Answer: 3

37.
37 The accepted value for the percent by mass of
   water in a hydrate is 36.0%. In a laboratory
   activity, a student determined the percent by
   mass of water in the hydrate to be 37.8%. What
   is the percent error for the student’s measured
   value?
   (1) 5.0%                  (3) 1.8%
   (2) 4.8%                  (4) 0.05%
Answer: 1

38.
38 The boiling points, at standard pressure, of four
   compounds are given in the table below.
     Boiling Points of Four Compounds
       Compound        Boiling Point (°C)
           H2O               100.0
           H2S              -59.6
           H2Se             -41.3
           H2Te               -2.0
   Which type of attraction can be used to explain
   the unusually high boiling point of H2O?
   (1) ionic bonding
   (2) hydrogen bonding
   (3) polar covalent bonding
   (4) nonpolar covalent bonding
Answer: 2

39.
39 Which formula represents a molecule with the
   most polar bond?
   (1) CO                (3) HI
   (2) NO                (4) HCl
Answer: 4

40.
40 The graph below represents the uniform
   heating of a substance from the solid to the gas
   phase.
Which line segment of the graph represents
boiling?

Answer: 4

41.
41 A 1-gram sample of a compound is added to
   100 grams of H2O(ℓ) and the resulting mixture
   is then thoroughly stirred. Some of the
   compound is then separated from the mixture
   by filtration. Based on Table F, the compound
   could be
   (1) AgCl                 (3) NaCl
   (2) CaCl2                (4) NiCl2
Answer: 1

42.
42 At standard pressure, the total amount of heat
   required to completely vaporize a 100.-gram
   sample of water at its boiling point is
   (1) 2.26 x 10 J           (3) 2.26 x 103 J
   (2) 2.26 x 102 J          (4) 2.26 x 105 J
Answer: 4

43.
43 A sample of helium gas is in a sealed, rigid
   container. What occurs as the temperature of
   the sample is increased?
   (1) The mass of the sample decreases.
   (2) The number of moles of gas increases.
   (3) The volume of each atom decreases.
   (4) The frequency of collisions between atoms
       increases.
Answer: 4

44.
44 Given the equation representing a reaction at
   equilibrium:
Which change causes the equilibrium to shift to
the right?
(1) adding a catalyst
(2) adding more O2(g)
(3) decreasing the pressure
(4) increasing the temperature
Answer: 2

45.
45 Given the formula representing a compound:
What is a chemical name of this compound?
(1) 2-pentene          (3) 3-pentene
(2) 2-pentyne          (4) 3-pentyne
Answer: 1

46.
46 What is the oxidation number of manganese in
   KMnO4?
   (1) +7                  (3) +3
   (2) +2                  (4) +4
Answer: 1

47.
47 When the pH of an aqueous solution is changed
   from 1 to 2, the concentration of hydronium
   ions in the solution is
   (1) decreased by a factor of 2
   (2) decreased by a factor of 10
   (3) increased by a factor of 2
   (4) increased by a factor of 10
Answer: 2

48.
48 What is the color of the indicator thymol blue in
   a solution that has a pH of 11?
   (1) red                    (3) pink
   (2) blue                   (4) yellow
Answer: 2

49.
49 Which formulas represent compounds that are isomers of each other?

Answer: 3

50.
50 One beneficial use of radioisotopes is
   (1) detection of disease
   (2) neutralization of an acid spill
   (3) decreasing the dissolved O2(g) level in seawater
   (4) increasing the concentration of CO2(g) in the atmosphere
Answer: 1


Part B–2
Answer all questions in this part.
   Directions (51–65): Record your answers in the spaces provided in your answer booklet. Some questions
may require the use of the 2011 Edition Reference Tables for Physical Setting/Chemistry.

51.
51 Draw a Lewis electron-dot diagram for a molecule of bromomethane, CH3Br. [1]
Answer: MODEL ANSWER GIVEN BELOW
51 [1] Allow 1 credit. The position of the electrons can vary.
        Examples of 1-credit responses:


52.
52 Explain, in terms of atomic structure, why Group 18 elements on the Periodic Table
   rarely form compounds. [1]
Answer: MODEL ANSWER GIVEN BELOW
52 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             Group 18 elements rarely form compounds because their atoms have stable electron
             configurations.
             Their valence shells are completely filled.
             All the elements have maximum numbers of valence electrons.
             Atoms of Group 18 have a stable octet except He, which is stable with two electrons.


53.
53 Explain, in terms of electrons, why the radius of a potassium atom is larger than the
   radius of a potassium ion in the ground state. [1]
Answer: MODEL ANSWER GIVEN BELOW
53 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             A potassium atom has four electron shells and a potassium ion has three electron shells.
             A potassium atom has one more electron shell than a potassium ion.
             A K+ ion has one fewer electron than a K atom.


54.
54 Identify the type of bonding in solid potassium. [1]
Answer: MODEL ANSWER GIVEN BELOW
54 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             metallic bonding
             metallic


55.
Base your answers to questions 55 and 56 on the information below and on your knowledge of chemistry.
          A 2.50-liter aqueous solution contains 1.25 moles of dissolved sodium chloride. The
      dissolving of NaCl(s) in water is represented by the equation below.
55 Determine the molarity of this solution. [1]
Answer: MODEL ANSWER GIVEN BELOW
55 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             0.500 M
             0.50 M
             .5 M


56.
56 Compare the freezing point of this solution to the freezing point of a solution
   containing 0.75 mole NaCl per 2.50 liters of solution. [1]
Answer: MODEL ANSWER GIVEN BELOW
56 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             The solution that contains 1.25 moles of NaCl has a lower freezing point.
             lower for the first one
             higher for the solution with 0.75 mol
             The 0.30 M solution has a higher freezing point than the 0.50 M solution.
             This solution has a lower f.p.


57.
Base your answers to questions 57 and 58 on the information below and on your knowledge of chemistry.
          A 1.00-mole sample of glucose, C6H12O6 , completely reacts with oxygen, as represented
      by the balanced equation below.
                       C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O(ℓ) + energy
      57 Write the empirical formula for glucose. [1]
Answer: MODEL ANSWER GIVEN BELOW
57 [1] Allow 1 credit for CH2O. The order of the elements can vary.


58.
58 Using the axes in your answer booklet, complete the potential energy curve for the
   reaction of glucose with oxygen. [1]
Answer: MODEL ANSWER GIVEN BELOW
58 [1] Allow 1 credit for showing both a peak that is higher than the beginning and the end of the curve and
       that the PE of the products is lower than the PE of the reactants.
        Example of a 1-credit response:


59.
Base your answers to questions 59 through 61 on the information below and on your knowledge of chemistry.
          Ethane, C2H6, has a boiling point of -89°C at standard pressure. Ethanol, C2H5OH,
      has a much higher boiling point than ethane at standard pressure. At STP, ethane is a gas
      and ethanol is a liquid.
      59 Identify the class of organic compounds to which ethanol belongs. [1]
Answer: MODEL ANSWER GIVEN BELOW
59 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             alcohol
             alcohols
             primary alcohol
             monohydroxy alcohols


60.
60 A liquid boils when the vapor pressure of the liquid equals the atmospheric pressure on
   the surface of the liquid. Based on Table H, what is the boiling point of ethanol at
   standard pressure? [1]
Answer: MODEL ANSWER GIVEN BELOW
60 [1] Allow 1 credit for any value from 78°C to 80.°C, inclusive.


61.
61 Compare the intermolecular forces of the two substances at STP. [1]
Answer: MODEL ANSWER GIVEN BELOW
61 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             Ethane has weaker intermolecular forces (IMF) than ethanol.
             Ethanol has hydrogen bonding.
             Van der Waals forces are weaker in C2H6.


62.
Base your answers to questions 62 through 65 on the information below and on your knowledge of chemistry.
         An operating voltaic cell has zinc and iron electrodes. The cell and the unbalanced ionic
      equation representing the reaction that occurs in the cell are shown below.
                                                 
          Zn(s) + Fe3+(aq)  →  Zn2+(aq) + Fe(s)
62 Identify the subatomic particles that flow through the wire as the cell operates. [1]
Answer: MODEL ANSWER GIVEN BELOW
62 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             electrons
             e-
             e


63.
63 Balance the equation in your answer booklet for the redox reaction that occurs in this
   cell, using the smallest whole-number coefficients. [1]
Answer: MODEL ANSWER GIVEN BELOW
63 [1] Allow 1 credit for


64.
64 Identify one metal from Table J that is more easily oxidized than Zn. [1]
Answer: MODEL ANSWER GIVEN BELOW
64 [1] Allow 1 credit for the symbol or name of any metal listed above Zn on Table J.


65.
65 Explain, in terms of Zn atoms and Zn ions, why the mass of the Zn electrode decreases
   as the cell operates. [1]
Answer: MODEL ANSWER GIVEN BELOW
65 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             Zinc atoms from the electrode are oxidized to zinc ions in the solution, decreasing the mass of
             the electrode.
             Zinc atoms become Zn2+(aq).
             The atoms become ions dissolved in the water.
             Zn atoms lose electrons, producing ions in solution.



Part C
Answer all questions in this part.
66.
   Base your answers to questions 66 through 69 on the information below and on your knowledge of
chemistry.
            A student compares some models of the atom. These models are listed in the table
        below in order of development from top to bottom.
                                           Models of the Atom
            Model                    Observation                           Conclusion
-----------------------------------------------------------------------------------------------------
 Dalton model                Matter is conserved during a            Atoms are hard, indivisible
                             chemical reaction.                      spheres of different sizes.
-----------------------------------------------------------------------------------------------------
 Thomson model               Cathode rays are deflected              Atoms have small, negatively
                             by magnetic/electric fields.            charged particles as part of their
                                                                     internal structure.
----------------------------------------------------------------------------------------------------- 
 Rutherford model            Most alpha particles pass               An atom is mostly empty space with
                             straight through gold foil but          a small, dense, positively charged
                             a few are deflected.                    nucleus.
----------------------------------------------------------------------------------------------------- 
 Bohr model                  Unique spectral lines are               Packets of energy are absorbed or
                             emitted by excited gaseous              emitted by atoms when an electron
                             elements.                               changes shells.
------------------------------------------------------------------------------------------------------
        
      66 State the model that first included electrons as subatomic particles. [1]
Answer: MODEL ANSWER GIVEN BELOW
66 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             Thomson model
             Thomson
             plum pudding model


67.
67 State one conclusion about the internal structure of the atom that resulted from the gold
   foil experiment. [1]
Answer: MODEL ANSWER GIVEN BELOW
67 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             An atom is mainly empty space.
             It has a nucleus.
             The small, dense nucleus is positively charged.


68.
68 Using the conclusion from the Rutherford model, identify the charged subatomic
   particle that is located in the nucleus. [1]
Answer: MODEL ANSWER GIVEN BELOW
68 [1] Allow 1 credit. Acceptable responses include, but are not limited to:


69.
69 State one way in which the Bohr model agrees with the Thomson model. [1]
Answer: MODEL ANSWER GIVEN BELOW
69 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             Atoms have electrons.
             Atoms have small, negatively charged particles.
             Both models show an internal structure.
             Atoms are neutral.


70.
   Base your answers to questions 70 through 72 on the information below and on your knowledge of
chemistry.
            Paintball is a popular recreational activity that uses a metal tank of compressed carbon
        dioxide or nitrogen to launch small capsules of paint. A typical tank has a volume of
        508 cubic centimeters. A 340.-gram sample of carbon dioxide is added to the tank before it
        is used for paintball. At 20.°C, this tank contains both CO2(g) and CO2(ℓ). After a paintball
        game, the tank contains only CO2(g).
        70 Determine the total number of moles of CO2 added to the tank before it is used for
           paintball. [1]
Answer: MODEL ANSWER GIVEN BELOW
70 [1] Allow 1 credit for 7.73 mol or for any value from 7.7 mol to 8 mol, inclusive.


71.
71 In the box in your answer booklet, use the key to draw a particle diagram to represent
   the two phases of CO2 in a newly filled tank. Your response must include at least six
   molecules of CO2 in each phase. [1]
Answer: MODEL ANSWER GIVEN BELOW
71 [1] Allow 1 credit. Molecules of the gas must be drawn farther apart than the molecules of the liquid.
        Examples of 1-credit responses:


72.
72 After the paintball game, the tank has a gas pressure of 6.1 atmospheres and is at
   293 K. If the tank is heated to 313 K, the pressure in the tank will change. Show a
   numerical setup for calculating the pressure of the gas in the tank at 313 K. [1]
Answer: MODEL ANSWER GIVEN BELOW
72 [1] Allow 1 credit. Acceptable responses include, but are not limited to:


73.
   Base your answers to questions 73 through 75 on the information below and on your knowledge of
chemistry.
            Many breads are made by adding yeast to dough, causing the dough to rise. Yeast is a
        type of microorganism that produces the catalyst zymase, which converts glucose, C6H12O6,
        to ethanol and carbon dioxide gas. The balanced equation for this reaction is shown below.
73 Draw a structural formula for the ethanol formed during this reaction. [1]
Answer: MODEL ANSWER GIVEN BELOW
73 [1] Allow 1 credit.
        Examples of 1-credit responses:


74.
74 Describe how the catalyst, zymase, speeds up this reaction. [1]
Answer: MODEL ANSWER GIVEN BELOW
74 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             Zymase is a catalyst that provides an alternative pathway, which requires less energy.
             decreases the activation energy
             changes the reaction mechanism


75.
75 Determine the total mass of ethanol produced when 270. grams of glucose reacts
   completely to form ethanol and 132 grams of carbon dioxide. [1]
Answer: MODEL ANSWER GIVEN BELOW
75 [1] Allow 1 credit for 138 g or for any value from 137.8 g to 138.3 g, inclusive.


76.
   Base your answers to questions 76 through 79 on the information below and on your knowledge of
chemistry.
            During a laboratory activity, a student places 25.0 mL of HCl(aq) of unknown
        concentration into a flask. The student adds four drops of phenolphthalein to the solution
        in the flask. The solution is titrated with 0.150 M KOH(aq) until the solution appears faint
        pink. The volume of KOH(aq) added is 18.5 mL.
        76 What number of significant figures is used to express the concentration of the
           KOH(aq)? [1]
Answer: MODEL ANSWER GIVEN BELOW
76 [1] Allow 1 credit for 3 or three.


77.
77 Complete the equation in your answer booklet for the neutralization reaction that
   occurs during the titration. [1]
Answer: MODEL ANSWER GIVEN BELOW
77 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             KCl(aq) + H2O(ℓ)
             K+ + Cl- + OH2(ℓ)
             HOH + ClK


78.
78 Determine the concentration of the HCl(aq) solution, using the titration data. [1]
Answer: MODEL ANSWER GIVEN BELOW
78 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             0.111 M
             0.11 M
             0.1 M


79.
79 Describe one laboratory safety procedure that should be used if a drop of the KOH(aq)
   is spilled on the arm of the student. [1]
Answer: MODEL ANSWER GIVEN BELOW
79 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             The student should immediately place his/her arm under running water to dilute and wash away
             the KOH(aq).
             Tell the teacher.


80.
   Base your answers to questions 80 through 82 on the information below and on your knowledge of
chemistry.
            A few pieces of dry ice, CO2(s), at -78°C are placed in a flask that contains air at 21°C.
        The flask is sealed by placing an uninflated balloon over the mouth of the flask. As the
        balloon inflates, the dry ice disappears and no liquid is observed in the flask.
        80 State the direction of heat flow that occurs between the dry ice and the air in the flask.
           [1]
Answer: MODEL ANSWER GIVEN BELOW
80 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             Heat flows from the air in the flask to the dry ice.
             air to CO2
             to dry ice
             from air


81.
81 Write the name of the process that occurs as the dry ice undergoes a phase change in
   the flask. [1]
Answer: MODEL ANSWER GIVEN BELOW
81 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             sublimation
             subliming


82.
82 Compare the entropy of the CO2 molecules in the dry ice to the entropy of the CO2
   molecules in the inflated balloon. [1]
Answer: MODEL ANSWER GIVEN BELOW
82 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             The CO2 molecules in the dry ice have less entropy than the CO2 molecules in the inflated
             balloon.
             The CO2 gas in the balloon is more disordered.
             less for CO2(s)


83.
   Base your answers to questions 83 through 85 on the information below and on your knowledge of
chemistry.
            Illuminated EXIT signs are used in public buildings such as schools. If the word EXIT is
        green, the sign may contain the radioisotope tritium, hydrogen-3. The tritium is a gas sealed
        in glass tubes. The emissions from the decay of the tritium gas cause a coating on the inside
        of the tubes to glow.
        83 State, in terms of neutrons, how an atom of tritium differs from an atom of
           hydrogen-1. [1]
Answer: MODEL ANSWER GIVEN BELOW
83 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
             A tritium atom has two neutrons and an H-1 atom has no neutrons.
             Only the tritium atom has neutrons.
             H-1 has no neutrons.


84.
84 Determine the fraction of an original sample of tritium that remains unchanged after
   24.62 years. [1]
Answer: MODEL ANSWER GIVEN BELOW
84 [1] Allow 1 credit. Acceptable responses include, but are not limited to:


85.
85 Complete the nuclear equation in your answer booklet for the radioactive decay of
   tritium, by writing a notation for the missing product. [1]
Answer: MODEL ANSWER GIVEN BELOW
85 [1] Allow 1 credit. Acceptable responses include, but are not limited to:



  Try the Quiz :     Physical Setting / Chemistry - New York Regents June 2014 Exam


Contact Info © 1999-2017 Syvum Technologies Inc. Privacy Policy Disclaimer and Copyright
Previous
-
Next
-