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. Topic 9 – Kinetics and Equilibrium
15. Equilibrium: Recalling concept facts and definitions
1. Which changes can reach equilibrium? 3) Both physical and chemical changes
1) Chemical changes, only
2) Physical changes, only 4) Neither physical nor chemical changes
2. Equilibrium process can be observed in
1) A reversible reaction in an open system 3) An irreversible reaction in an open system
2) A reversible reaction in a closed system 4) An irreversible reaction in a closed system
3. At equilibrium, the concentration of the products and of the reactants are
1) Equal 3) Increasing
2) Constant 4) Decreasing
4. At equilibrium, the rates at which the forward and the reverse processes are occurring are
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1) Equal 3) Increasing
2) Constant
4) Decreasing
5. A chemical reaction has reached equilibrium when
1) The forward and reverse reactions are occurring at equal rate
2) The forward and reversible reactions are occurring at different rate
3) The concentration of the substances are equal
4) The concentration of the reactants have been used up
6. Which factor must be equal when a reversible chemical process reaches equilibrium?
1) Mass of the reactant and mass of the products
2) Rate of the forward reaction and rate of the reverse reaction
3) Concentration of the reactants and the concentration of the products
4) Activation energy of the forward reaction and the activation energy of the reverse reaction
7. A system is said to be in a state of dynamic equilibrium when the
1) Concentration of products is greater than the concentration of the reactants
2) Concentration of products is the same as the concentration of the reactants
3) The rate at which products are formed is greater than the rate at which the reactants are formed
4) The rate at which products are formed is the same as the rate at which the reactants are formed
8. Given the reaction at STP:
N2O4(g) < ========= > 2NO2(g)
Which statement correctly describes this system?
1) The reaction is at equilibrium, and the concentration of N2O4 and NO2 are equal
2) The reaction is NOT at equilibrium, and the concentration of N2O4 and NO2 are equal
3) The reaction is at equilibrium, and the forward and reverse reaction rates are equal
4) The reaction is NOT at equilibrium, and the forward and the reverse reaction rates are equal
9. Given the reaction + -
AgCl(s) < ----------------- > Ag (aq) + Cl (aq)
When equilibrium is reached, which statement is accurate?
-(
+
1) The concentration of AgCl(s), Ag (aq) and Cl aq) are all equal
-
+
2) The concentration of AgCl(s), Ag (aq) and Cl (aq) are all constant
3) The rate of dissolving of AgCl(s) is greater than the rate of crystallization of Ag+(aq) and Cl (aq)
-
-
+
4) The rate of crystallization of Aq (aq) and Cl (aq) is greater than the rate of dissolving of AgCl(s)
Copyright©2010 E3 Scholastic Publishing. All Rights Reserved. SurvivingChem.com 281
15. Equilibrium: Recalling concept facts and definitions
1. Which changes can reach equilibrium? 3) Both physical and chemical changes
1) Chemical changes, only
2) Physical changes, only 4) Neither physical nor chemical changes
2. Equilibrium process can be observed in
1) A reversible reaction in an open system 3) An irreversible reaction in an open system
2) A reversible reaction in a closed system 4) An irreversible reaction in a closed system
3. At equilibrium, the concentration of the products and of the reactants are
1) Equal 3) Increasing
2) Constant 4) Decreasing
4. At equilibrium, the rates at which the forward and the reverse processes are occurring are
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1) Equal 3) Increasing
2) Constant
4) Decreasing
5. A chemical reaction has reached equilibrium when
1) The forward and reverse reactions are occurring at equal rate
2) The forward and reversible reactions are occurring at different rate
3) The concentration of the substances are equal
4) The concentration of the reactants have been used up
6. Which factor must be equal when a reversible chemical process reaches equilibrium?
1) Mass of the reactant and mass of the products
2) Rate of the forward reaction and rate of the reverse reaction
3) Concentration of the reactants and the concentration of the products
4) Activation energy of the forward reaction and the activation energy of the reverse reaction
7. A system is said to be in a state of dynamic equilibrium when the
1) Concentration of products is greater than the concentration of the reactants
2) Concentration of products is the same as the concentration of the reactants
3) The rate at which products are formed is greater than the rate at which the reactants are formed
4) The rate at which products are formed is the same as the rate at which the reactants are formed
8. Given the reaction at STP:
N2O4(g) < ========= > 2NO2(g)
Which statement correctly describes this system?
1) The reaction is at equilibrium, and the concentration of N2O4 and NO2 are equal
2) The reaction is NOT at equilibrium, and the concentration of N2O4 and NO2 are equal
3) The reaction is at equilibrium, and the forward and reverse reaction rates are equal
4) The reaction is NOT at equilibrium, and the forward and the reverse reaction rates are equal
9. Given the reaction + -
AgCl(s) < ----------------- > Ag (aq) + Cl (aq)
When equilibrium is reached, which statement is accurate?
-(
+
1) The concentration of AgCl(s), Ag (aq) and Cl aq) are all equal
-
+
2) The concentration of AgCl(s), Ag (aq) and Cl (aq) are all constant
3) The rate of dissolving of AgCl(s) is greater than the rate of crystallization of Ag+(aq) and Cl (aq)
-
-
+
4) The rate of crystallization of Aq (aq) and Cl (aq) is greater than the rate of dissolving of AgCl(s)
Copyright©2010 E3 Scholastic Publishing. All Rights Reserved. SurvivingChem.com 281
