Name: Date: Period: REVIEW CHAPTERS 10 AND 18 1. Identify the type of each of the following reactions: a. 2Mg + O 2 2 MgO Synthesis b. Fe + CuSO 4 FeSO 4 + Cu Single-Replacement (SR) c. CaCO 3 CaO + CO 2 Decomposition d. NaCl + AgNO 3 NaNO 3 + AgCl Double-Replacement (DR) e. 2 C 4 H 10 + 13 O 2 8 CO 2 + 10 H 2 O Combustion 2. Balance the following chemical reactions. a. C 3 H 8 + 5 O 2 3 CO 2 + 4 H 2 O b. N 2 + 3 H 2 2 NH 3 c. 2 AlBr 3 + 3 K 2 SO 4 6 KBr + Al 2 (SO 4 ) 3 d. S 8 + 12 O 2 8 SO 3 e. 2 Al + 6 HCl 3 H 2 + 2 AlCl 3 3. Why do we balance chemical equations (by adding coefficients)? To obey the law of conservation of matter (matter cannot be created or destroyed) 4. Why don t we change subscripts when balancing equations? Changing subscripts would change the compound itself 5. What are the seven diatomic elements and their formulas? (Holy Seven) H 2 N 2 O 2 F 2 Cl 2 Br 2 I 2 6. What are the formulas and names for the simplest hydrocarbon compounds containing 1 to 4 carbons? Methane CH 4 ; Ethane C 2 H 6 ; Propane C 3 H 8 ; Butane C 4 H 10 7. Be able to identify the correct formulas and symbols for the compounds and elements involved in a chemical reaction and then balance the reaction. a. Zinc and oxygen gas react to form zinc oxide 2 Zn + O 2 2 ZnO b. Potassium metal and chlorine gas combine to form potassium chloride 2 K + Cl 2 2 KCl c. Methane and oxygen react to form carbon dioxide and water CH 4 + 2 O 2 CO 2 + 2 H 2 O 8. According to the collision theory, what has to occur for a reaction to take place? a. Must collide b. Must collide in proper orientation c. Must collide with enough energy to break chemical bonds
9. Compare the two potential energy diagrams for A B. a) Label each diagram as either exothermic or endothermic EXOTHERMIC ENDOTHERMIC b) Identify what each of the letters represents in the energy diagrams: Left Diagram Right Diagram (a) Activation Energy (Forward) (a) Activation Energy (Forward) (b) Activation Energy (Reverse) (b) Activation Energy (Reverse) (c) Heat of Reaction ( H) (c) Heat of Reaction ( H) c) In each diagram, sketch the curve if a catalyst is used. d) For each curve, what is the value of the activation energy? Left graph: 50 (forward); 150 (reverse) Right graph: 300 (forward); 100 (reverse) e) For each curve, what is the heat of reaction? Left graph: 100 (forward); + 100 (reverse) Right graph: +200 (forward); 200 (reverse) 10. Using the following graph of the hypothetical reaction A B, answer the questions that follow. a. Identify the product and reactant: Product = B; Reactant = A b. What happens to the number of moles of reactants over time? Decreases c. What happens to the number moles of products over time? Increases d. At what time is the number of moles of each at a maximum and a minimum? A(0 min = max; 60 min = min); B(60 min = max; 0 min = min) e. At what time are the number of moles of A and B the same? About 23 min
11. What is the definition of chemical rate of reaction? (two options) Disappearance of reactants over time ( amount of reactants/ time) Appearance of products over time ( amount of products/ time) 12. What factors affect the rate of a reaction? Explain how each affects the rate. Temperature increasing temperature increases rate by increasing speed of molecules (increase speed = increase collisions = increase collision energy) Surface area increasing surface area increases rate by allowing more sites of reactions (more surfaces for reaction to occur = quicker reaction) Concentration increasing concentration increases rate by creating more collisions (more concentrated = more particles in a given space = more collisions) Catalyst increases rate of reaction by lowering activation energy (lower activation energy = more collisions result in products) 13. What is the definition of chemical equilibrium of a reversible reaction? Rate of forward reaction and reverse reaction are equal and the concentrations (amount) of products and reactants remains constant. 14. Using the following equation at equilibrium, answer the following questions: Heat + H 2 (g) + F 2 (g) 2 HF (g) a. What direction will the reaction shift if heat is added? Right ( ) b. What direction will the reaction shift is pressure is increased? No shift (equal # of molecules) c. What will happen to the concentration of H 2 if the temperature decreases? Increases (shifts left) d. What will happen to the concentration of HF if more F 2 is added? Increases (shifts right) e. What direction will the reaction shift if more HF is added? Left ( ) 15. Using the following equation at equilibrium, answer the following questions: 2 H 2 (g) + O 2 (g) 2 H 2 O (g) + Heat a. What direction will the reaction shift if heat is added? Left ( ) b. What direction will the reaction shift is pressure is increased? Right ( ) c. What will happen to the concentration of H 2 if the temperature increases? Increases (shifts left)
16. At what time does this reaction achieve equilibrium? 80 seconds 17. What is the concentration of B at equilibrium? 0.8 18. What is the concentration of A at equilibrium? 0.2 19. For the reaction A + B C + D + heat, propose 4 different stresses that you could put on the system that would increase the amount of D produced. Increase A Increase B Decrease C Decrease heat 19. a) Make of sketch of each of the compounds in the reaction below. Represent each atom by a circle and label each atom with its symbol. If atoms are bonded together they should touch. The LEAST electronegative will be in the center of the molecule. For example, SO 2 would be O-S-O. CO + NO 2 CO 2 + NO b) Now sketch the activated complex. What two atoms need to collide in order for the products to form? c) Draw a dotted line through your activated complex showing where the bonds will break to form your product.
d) Use the graph above: What is the value of the activation energy for this reaction? 10 e) Use the graph above: What is the value of the heat of reaction? 20 20. Write the following equations and predict the products for the following single and double replacement reactions. Be sure to balance the equation: Single Replacement: a. Aluminum + hydrochloric acid 2 Al + 6 HCl 3 H 2 + 2 AlCl 3 b. Fluorine + potassium bromide F 2 + 2 KBr Br 2 + 2 KF c. Lithium + lead(ii) nitrate 2 Li + Pb(NO 3 ) 2 Pb + 2 LiNO 3 Double Replacement a. Lithium carbonate + barium chloride Li 2 CO 3 + BaCl 2 BaCO 3 + 2 LiCl b. Lead (II) nitrate + iron (III) sulfate 3 Pb(NO 3 ) 2 + Fe 2 (SO 4 ) 3 2 Fe(NO 3 ) 3 + 3 PbSO 4