ChemistryName :
Worksheet : Ch. 18 : Obj. 1-15Date :
A. Read pp. 541-547 and answer the following questions :
1. The ______of a reaction is the number of atoms, ions or molecules that react in a given time to form products.
2. _____(T/F) The collision theory states that in order for reactants to react with each other they must collide with each other.
3. _____(T/F) In order for reactants to react with each other they must collide with a sufficient amount of energy for bond breaking and bond forming.
4. ______energy is the minimum amount of energy colliding particles must have in order to react.
5. ______are temporary arrangements of atoms at the peak of the energy barrier.
6. _____(T/F) Activated complexes, or transition states, are very stable arrangements of atoms.
7. List four factors which affect reaction rates and state how they affect reaction rates.
8. _____(T/F) Dissolving solid reactants is a way to increase their surface area.
9. _____ (T/F) Heterogeneous mixtures (e.g. a solid reactant and a gaseous reactant) generally react faster than homogenous mixtures (e.g. two aqueous reactants).
10. _____(T/F) Heterogeneous reactions are carried out in a homogenous mixture of reactants.
11. ______are substances which increase the rate of reaction without being used up or changing.
12. _____(T/F) Catalysts generally increase the activation energy needed to start a reaction.
13. ______are biological catalysts and increase the rates of reactions in living organisms.
14. ______are substances which interfere with catalysts to prevent them from increasing reaction rate.
15. Match the parts of the following diagram.
_____ activation energy
_____ energy absorbed or released
_____ reactants
_____ products
16. Is this an endothermic or exothermic reaction?
17. _____(T/F) The activation energy of the above diagram would be greater with a catalyst.
B. Read pp. 575 - 579 and answer the following questions.
18. The ______is an expression which relates the rate of a reaction to the concentration of the reactants.
19. The ______for a reaction (k) is a proportionality constant relating the concentration of reactants to the reaction rate.
20. _____(T/F) For a fast reaction the value of k will be small.
21. ______are reactions in which the reaction rate is proportional to the concentration of only one reactant.
22. ______reactions are reactions in which the reactants are converted into the products in a single step.
23. ______reactions involve many steps or elementary reactions.
24. The ______is the pathway of a complex reaction and includes all the elementary reactions.
25. ______are the products of one reaction before it changes as a reactant in another reaction.
26. _____(T/F) Intermediates and activated complexes are the same thing.
27. _____(T/F) Intermediates are always shown in the balanced chemical equation for a reaction.
28. _____(T/F) A balanced chemical equation indicates the reaction mechanism of a reaction.
C. Read pp. 566 - 573 and answer the following :
29. ______is the energy released from a system that is available to do work.
30. ______reactions take place naturally and form products at the specified conditions.
31. ______reactions do not take place naturally at the specified conditions.
32. _____(T/F)Chemical systems tend to the lowest possible states of energy.
33. _____(T/F) Chemical systems tend toward higher states of order.
34. ______is a measure of the disorder of a system.
35. State the law of disorder.
36. _____(T/F) Liquids have more entropy than gases.
37. _____(T/F) Solids have more entropy than liquids.
38. _____(T/F) A reaction which forms a gas from liquid reactants decreases entropy.
39. _____(T/F)Entropy increases when the total number of particles of the products is greater than the total number of particles in the reactants.
40. _____(T/F) Entropy increases in exothermic reactions.