NY Regents Chemistry Exam June 2019
Questions 21-30
21 Which value is defined as the difference between the potential energy of the products and the potential energy of the reactants during a chemical change? (1) heat of fusion (2) heat of reaction (3) heat of deposition
(4) heat of vaporization
Solution: Heat of reaction is the difference between the potential energy of the products and the potential energy of the reactants during a chemical change
Answer: Choice 2
22 The effect of a catalyst on a chemical reaction is to provide a new reaction pathway that results in a different (1) potential energy of the products
(2) heat of reaction (3) potential energy of the reactants
(4) activation energy
Solution: A catalyst is a substance that speeds up the reaction by lowering the activation energy.
Answer: Choice 4
23 Chemical systems in nature tend to undergo changes toward (1) lower energy and lower entropy
(2) lower energy and higher entropy
(3) higher energy and lower entropy
(4) higher energy and higher entropy
Solution: Chemical systems in nature tend to undergo changes toward higher entropy and lower energy.
Answer: Choice 2
24 The atoms of which element bond to one another in chains, rings, and networks? (1) barium
(2) carbon
(3) iodine
(4) mercury
Solution: Carbon is the element that is crucial to organic molecules. It can form chains, rings and networks.
Answer: Choice 2
25 What is the general formula for the homologous series that includes ethene? (1) CnH2n
(2) CnH2n+6
(3) CnH2n+2
(4) CnH2n+2
Solution: Ethene ends in "ene" which means it is an alkene. Table Q on the Reference Table shows the correct formula for alkenes, CnH2n
Answer: Choice 1 is correct
26 When an F atom becomes an F- ion, the F atom
(1) gains a proton
(2) loses a proton
(3) gains an electron
(4) loses an electron
Solution: When F atom gains an electron, it becomes F- ion (an electron has a -1 charge)
Answer: Choice 3
27 Which substance is an Arrhenius base?
(1) HNO3
(2) H2SO3 (3) Ca(OH)2
(4) CH3COOH
Solution: Table L on the Reference Table lists all the common bases.
Answer: Choice 3
28 In which type of nuclear reaction do two light nuclei combine to produce a heavier nucleus? (1) positron emission
(2) gamma emission
(3) fission
(4) fusion
Solution: Fusion is a nuclear reaction where light nuclei combine to produce a heavier nucleus
Answer: Choice 4
29 Using equal masses of reactants, which statement describes the relative amounts of energy released during a chemical reaction and a nuclear reaction?
(1) The chemical and nuclear reactions release equal amounts of energy.
(2) The nuclear reaction releases half the amount of energy of the chemical reaction.
(3) The chemical reaction releases more energy than the nuclear reaction.
(4) The nuclear reaction releases more energy than the chemical reaction.
Solution: Nuclear reactions such as fission and fusion release more energy than
Answer: Choice 4
30 The ratio of the mass of U-238 to the mass of Pb-206 can be used to (1) diagnose thyroid disorders
(2) diagnose kidney function
(3) date geological formations
(4) date once-living things
Solution: U-238 is used for figuring out the age of geological formations.
Answer: Choice 3
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