June 2008 Chemistry Regents #21-30
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|21 How is a chemical reaction affected by the addition of
(1) The activation energy decreases.
(2) The heat of reaction increases.
(3) The number of collisions between particles decreases.
(4) The potential energy of the reactants increases.
|1||Catalyst-lowers act. energy|
|22 Systems in nature tend to undergo changes toward
(1) lower energy and less disorder
(2) lower energy and more disorder
(3) higher energy and less disorder
(4) higher energy and more disorder
|2||exothermic and increase in entropy|
|23 What can be concluded if an ion of an element is
smaller than an atom of the same element?
(1) The ion is negatively charged because it has fewer electrons than the atom.
(2) The ion is negatively charged because it has more electrons than the atom.
(3) The ion is positively charged because it has fewer electrons than the atom.
(4) The ion is positively charged because it has more electrons than the atom.
|3||ions are smaller when they have lost an electron|
|24 Which class of organic compounds has molecules that
contain nitrogen atoms?
(1) alcohol (3) ether
(2) amine (4) ketone
|25 Which two compounds have the same molecular formula but
different chemical and physical properties?
(1) CH3CH2Cl and CH3CH2Br
(2) CH3CHCH2 and CH3CH2CH3
(3) CH3CHO and CH3COCH3
(4) CH3CH2OH and CH3OCH3
|4||count atoms they have to have the
just a different arrangement
|26 Which half-reaction equation represents the
reduction of a potassium ion?
(1) K+ + e-- ==>K (3) K+ ==>K + e--
(2) K + e-- ==> K+ (4) K==> K+ + e--
|1||charge goes down
electron on the more positive side
|27 According to the Arrhenius theory, an acid is
(1) changes litmus from red to blue
(2) changes phenolphthalein from colorless to pink
(3) produces hydronium ions as the only positive ions in an aqueous solution
(4) produces hydroxide ions as the only negative ions in an aqueous solution
|28 Which type of reaction occurs when a high energy
particle collides with the nucleus of an atom, converting that atom to
an atom of a different element?
(1) addition (3) substitution
(2) neutralization (4) transmutation
|4||definition of transmutation|
|29 Which particle is emitted when an atom of 85Kr
(1) an alpha particle (3) a neutron
(2) a beta particle (4) a proton
|2||Use Decay Mode from Table N|
|30 What is a problem commonly associated with nuclear
(1) A small quantity of energy is produced.
(2) Reaction products contribute to acid rain.
(3) It is impossible to control nuclear fission.
(4) It is difficult to dispose of wastes
|4||Use your brian|
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