Name__________________________________________period____________IB Chapter 6
Kinetics
1. Define the term rate of reaction.
2. What are some ways that we can measure the rate of a reaction?
3. Describe the collision theory
4. Describe the effect of a catalyst on a chemical reaction.
5. Define the term activation energy
6. It is found that a 10 oC increase in temperature roughly doubles the rate of many chemical reactions. If a reaction
takes 20 seconds at 40oC, how long would it take at 60oC?
7. Use the collision theory to explain why each factor (temperature, concentration, pressure, particle size) alters the
rate of a reaction.
8. It has been found that rates are more rapid at the beginning of a reaction than toward the end, assuming the
temperature is constant. Explain why.
9. Would you expect a packet of sugar to dissolve faster in hot tea or iced tea?
10. For each of the following pairs, choose the substance or process you would expect to react more rapidly.
a. Granulated sugar or powdered sugar
b. Zinc in HCl at 298 K or zinc in HCl at 410 K
c. 5 g of thick platinum wire or 5 g of thin platinum wire
11. Explain why there is a danger of explosion in places such as coal mines, saw mills, and grain elevators, were large
amounts of dry, powdered combustible materials are present.
12. For each energy diagram below, label reactants, products, ∆H, Ea, and tell if it is endothermic or exothermic.
13. How would each of the energy diagrams in the previous problem change if a catalyst were added to the reaction?
(show using dashed lines)
Try all the exercises and practice questions in Chapter 6
Review:
14. What is the concentration of nitric acid if 15 cm3 of it is titrated with 25 cm3 of 0.67 mol dm-3 aluminum hydroxide?
15.
The heat of solution for silver nitrate is +22.8 kJ/mol.
a. Is dissolving silver nitrate endothermic or exothermic?
b. As silver nitrate dissolves, what change occurs in the temperature of the solution?
c. How will increased temperature affect the amount of solute that can be dissolved?
d. Is silver nitrate more likely to dissolve in oil (nonpolar) or water (polar)?
16. What is the concentration of a solution if 40.3 g of potassium cyanide are dissolved 450 cm3 of solution?
17. How many grams of sodium hydroxide are in 210 cm3 of a 0.67 mol dm-3 solution?
18. How do gases compare with liquids and solids in terms of distance between their molecules?
19. Which of the following gases would have the greatest kinetic energy, He at 20 °C or He at 50 °C?
20. What is sublimation? Is it endothermic or exothermic?
21. Is melting endothermic or exothermic?
22. Is condensation endothermic or exothermic?
23. Label each of the following as exothermic or endothermic and tell if the temperature would increase or decrease
when the reaction occurs.
a. 2H2 + O2  2 H2O ∆H = 483.6 kJ
b. 2NO  N2 + O2
∆H = -90.29 kJ
24. What type of intermolecular forces does each of the following have?
a. CH4
b. NH3
c. H2O
d. H2S
25. Which of the following molecules in the previous question would have the lowest boiling point?
26. If 6.5 moles of hydrogen reacts with silver phosphate, how many grams of silver will be produced?
27. If M represents a group 1 metal, what is the formula for the compound formed by M and oxygen?
a. MO2
b. M2O
c. M2O3
d. M3O2
28. When do electrons release photons(packets of energy)? When the electrons:
a. move to higher levels of energy
b. return to their original energy level
c increase orbital speed around the nucleus
d. are released by the atom
29. Which of the following elements has the strongest attraction for electrons?
a. boron
b. aluminum
c. oxygen
d. sulfur
30. As the elements in Group 17 are considered in order of increasing atomic number, the chemical reactivity of each
successive element:
a. decreases
b. increases
c. remains the same