Chemistry 23 June 2015 Questions Answer keys
The University Of The State Of New York
Regents High School Examination
Tuesday, June 23, 2015 — 9:15 a.m. to 12:15 p.m., only
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. Compared to an electron, which particle has a charge that is equal in magnitude but opposite in sign?
- (1) an alpha particle
- (2) a beta particle
- (3) a neutron
- (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
- (2) atomic radius
- (3) melting point
- (4) electronegativity
4. Any substance composed of two or more elements that are chemically combined in a fixed proportion is
- (1) an isomer
- (2) an isotope
- (3) a solution
- (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
- (2) barium oxide
- (3) iodine
- (4) silver
7. What is the number of electrons shared between the carbon atoms in a molecule of ethyne?
- (1) 6
- (2) 2
- (3) 8
- (4) 4
8. Which atom in the ground state has a stable valence electron configuration?
- (1) Ar
- (2) Al
- (3) Si
- (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 Cl2(g) at STP?
- (1) 1.0 L of NH3(g)
- (2) 2.0 L of CH4(g)
- (3) 3.0 L of CO2(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
- (3) joules per kilogra
- (2) milliliters
- (4) moles per liter
13. Compared to the boiling point and the freezing point of water at 1 atmosphere, a 1.0 M CaCl2(aq) solution at 1 atmosphere has a
- (1) lower boiling point and a lower freezing point
- (2) lower boiling point and a higher freezing point
- (3) higher boiling point and a lower freezing point
- (4) higher boiling point and higher freezing point
14. According to the kinetic molecular theory, which statement describes an ideal gas?
- (1) The gas particles are diatomic.
- (2) Energy is created when the gas particles collide.
- (3) There are no attractive forces between the gas particles.
- (4) The distance between the gas particles is small, compared to their size.
15. Which physical change is endothermic?
- (1) CO2(s) → CO2(g)
- (2) CO2(ℓ) → CO2(s)
- (3) CO2(g) → CO2(ℓ)
- (4) CO2(g) → CO2(s)
16. Which Group 16 element combines with hydrogen to form a compound that has the strongest hydrogen bonding between its molecules?
- (1) oxygen
- (2) selenium
- (3) sulfur
- (4) tellurium
17. Hydrocarbons are composed of the elements
- (1) carbon and hydrogen, only
- (2) carbon and oxygen, only
- (3) carbon, hydrogen, and oxygen
- (4) carbon, nitrogen, and oxygen
18. Which atom is bonded to the carbon atom in the functional group of a ketone?
- (1) fluorine
- (2) hydrogen
- (3) nitrogen
- (4) oxygen
19. Two types of organic reactions are
- (1) addition and sublimation
- (2) deposition and saponification
- (3) decomposition and evaporation
- (4) esterification and polymerization
20. The isomers butane and methylpropane have
- (1) the same molecular formula and the same properties
- (2) the same molecular formula and different properties
- (3) different molecular formulas and the same properties
- (4) different molecular formulas and different properties
21. In a redox reaction, which particles are lost and gained in equal numbers?
- (1) electrons
- (2) neutrons
- (3) hydroxide ions
- (4) hydronium ions
22. What is the oxidation state for a Mn atom?
- (1) 0
- (2) 7
- (3) 3
- (4) 4
23. Which compounds are classified as electrolytes?
- (1) KNO3 and H2SO4
- (2) KNO3 and CH3OH
- (3) CH3OCH3 and H2SO4
- (4) CH3OCH3 and CH3OH
24. Which compound is an Arrhenius base?
- (1) CO2
- (2) CaSO4
- (3) Ca(OH) 2
- (4) C2H5OH
25. According to one acid-base theory, a water molecule acts as a base when it accepts
- (1) an H+ion
- (2) an OH– ion
- (3) a neutron
- (4) an electron
26. Given the equation representing a system at equilibrium:
N2(g) 3H2 (g) 2NH3(g)
Which statement describes this reaction at equilibrium?
- (1) The concentration of N2(g) decreases.
- (2) The concentration of N2 (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
- (2) fermentation
- (3) titration
- (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
- (2) fusion
- (3) deposition
- (4) evaporation
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