Exam - Faculty.utep.edu

145) To make a chemical reaction occur, the activation energy is the energy that
A) must be removed from the mixture.
B) must be released from the mixture.
C) initiates the reaction.
D) activates the catalyst.
E) is the difference in the energies of the starting materials and products.
146) A chemical reaction has reached equilibrium when
A) the concentrations of reactants and products are equal.
B) all reactants have been converted to products.
C) all products have been removed from the reaction mixture.
D) the catalyst has been used up.
E) the rate of the forward reaction equals the rate of the reverse reaction.
147) In an oxidation-reduction reaction, the substance oxidized always
A) takes on oxygen atoms.
B) shows a loss of electrons.
C) gives up hydrogen atoms.
D) shows a gain of electrons.
E) becomes a charged species.
148) In this reaction, what is the substance oxidized
Zn + 2 HCl ¬ ZnCl2 + H2
A) chlorine B) zinc chloride C) hydrogen D) Zn E) oxygen
149) In an oxidation-reduction reaction, the substance reduced always
A) takes on oxygen atoms.
B) shows a loss of electrons.
C) gives up hydrogen atoms.
D) shows a gain of electrons.
E) becomes a charged species.
150) In this reaction, what is the substance reduced
2H2 + O2 ¬ 2H2O
A) hydrogen
B) oxygen
C) water
D) heat
E) Reduction does not take place.
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