Welcome to Navigate Powered by NIDES Chemistry 12! Please note that the First Assignment is a requirement to be registered in the course. Legal last name: First name: Student Email: Cell Phone #: Other last name: Middle name: Parent or guardian email: Home phone#: Other school attending: Instructions: This assignment is intended to take approximately 5-10 hours to complete. It is worth 10% of your final grade for the course, so complete it carefully: 1. Read each question carefully before answering 2. Answer all questions to the best of your ability, and in your own words. Plagiarized assignments will not be accepted, and you will not be registered in the course. 3. Take your time and explore all of the resources. You will receive a higher mark on your First Assignment if you include your learning from the readings and resources provided. Contact the Chemistry 12 teacher for help if needed. Teacher contact information can be found on the Navigate website or attach the scan to your registration form, or fax to 250-337-2310 or mail to North Island Distance Education School 2505 Smith Road Courtenay, BC Canada V9J 1T6 4. If you scan is too big to send in one email, reset your scanner to a lower quality, or use a program like http://www.picresize.com/ to resize the document 5. When you have completed this assignment, return it as an attachment to an email to: registrar@sd71.bc.ca or attach it to your registration form Office Use Only Date: Learning Guide /20 Summary Questions /21 Assignment total: /41 Teacher feedback:
Unit 1 ~ Learning Guide Name: Instructions: Using a pencil, complete the following notes as you work through the related lessons. Show ALL work as is explained in the lessons. You are required to have this package completed BEFORE you write your unit test. Do your best and ask questions if you don t understand anything! Some questions have hints at the end of the learning guide. Try questions on your own before using them. Please print out the Formula Sheet and found at the start of the course. You will need this to do assignments and tests! Reaction Rates: 1. What is the definition of a reaction rate? 2. For each of the following write i) a balanced chemical formula equation, ii) a complete ionic equation and iii) a net ionic equation. a) Magnesium metal is placed in a solution of hydrochloric acid and reacts to form aqueous magnesium chloride and hydrogen gas i) ii) iii) b) Aqueous chlorine is added to a solution of aluminum bromide in a single replacement reaction which forms no precipitate and bromine liquid. i) ii) iii) Page 1 of 13
3. For the following questions use the reaction in question 2a) a) There are five possible rate equations that could be used to measure the reaction rate. Write two of these possible rate equations. b) What is the spectator ion for this reaction? c) If 0.0586 L of hydrogen gas is collected in 5.00 minutes, calculate the rate of the reaction in ml of hydrogen gas per second. d) Using the reaction rate you calculated above, calculate the volume of hydrogen as produced in 23.0 minutes. e) Using the reaction rate you calculated above, calculate how long in minutes it takes to produce 1.50 L H 2. Page 2 of 13
4. Use the reaction below to answer the following questions. 2 Ag (s) + Zn(NO 3 ) 2(aq) Zn (s) + 2 Ag(NO 3 ) 2(aq) a) It is found that the rate of production of Zn(s) is 10.7 g/s. Calculate the mass of silver (in kg) reacted in 15.2 minutes. b) If 14.3g of silver is used up in 5.0 minutes, what mass of zinc (in g) is formed in 45 seconds? 5. What is the rate of reaction at 20 seconds? You will need to draw a tangent line. It can be tricky to draw a perfect tangent line so don't worry if your answer does not exactly match the answer key. 70 60 50 40 Mass (g) 30 20 10 0 0 20 40 Time (s) 60 80 100 120 Page 3 of 13
6. What are four factors that affect a reaction rate? 7. List five ways you can increase the reaction rate of the reaction below. 6 Mg (s) + 1 N 2(g) 2 Mg 3 N (s) 8. Is the reaction in question 7 homogeneous or heterogeneous and how do you know? Collision Theory and Heat of Reaction: 1. What two factors determine whether or not a collision of molecules will successfully result in a reaction? 2. What is the definition of activation energy (E A )? Page 4 of 13
3. When molecules are oriented correctly and collide with sufficient kinetic energy what is formed? 4. a) What type of energy increases as two molecules approach each other? b) What type of energy decreases as two molecules approach each other? 5. What is temperature's role in a reaction? 6. Place the correct numbers for each label in the correct circle. Memorize! Page 5 of 13
7. The Enthalpy change ( H) for an exothermic reaction will always be (positive/negative)? 8. The Enthalpy change ( H) for an endothermic reaction will always be (positive/negative)? 9. The Activation Energy (EA) for ALL reaction will always be (positive/negative)? 10. Use the graph in question 6 to answer the following questions? Show your work! Be sure to indicate + or - correctly. a) What is the value of E A forward? b) What is the value of H forward? c) What is the value of E A reverse? d) What is the value of H reverse? e) What is the energy of the Activated Complex? f) Will the reactants or products have the strongest bonds? Explain how you know. Page 6 of 13
11. Use the following information to draw a potential energy diagram. You must first calculate H forward and H reverse. Fully label your diagram similar to question 6. E A Forward = + 45 kj E A Reverse = +30 kj Activated Complex Energy = 70 kj 12. What is the energy of the reactants in question 11? 13. What is the energy of the products question 1? 14. Is the reaction described in question 11 exothermic or endothermic? Explain how you know. Page 7 of 13
14. There are a few definitions of Enthalpy. In this course what should we mainly consider Enthalpy to be? 15. State whether each of the following reactions is exothermic or endothermic. Reaction Exo or Endo 2 C 8 H 18 + 25 O 2 16 CO 2 + 16 H 2 O + 10110 kj Ba(OH) 2 + 2 NH 4 Cl + 430 kj BaCl 2 + 2 NH 4 OH SOCl 2 + CoCl 2 6H 2 O CoCl 2 + HCl + 6 SO 2 H = +360 kj Mn (s) + 2 HCl (aq) MnCl 2(aq) + H 2(g) H = -221 kj 16. If you drop calcium into water do you get an exothermic or endothermic reaction? 17. Determine which of the following reactions is faster and explain your reasoning. a) 2 Ag (s) + Zn(NO 3 ) 2(aq) Zn (s) + 2 Ag(NO 3 ) 2(aq) b) BaCl 2(aq) + Pb(NO 3 ) 2(aq) PbCl 2(s) + Ba(NO 3 ) 2(aq) 18. Determine which of the following reactions is faster and explain your reasoning. a) Cl 2(g) + Br 2(g) 2 BrCl (g) b) 3 H 2(g) + N 2(g) 2 NH 3(g) Page 8 of 13
Kinetic Energy and Reaction Mechanisms: 1. What is the rule of thumb regarding temperature increases and their effect on reaction rates? 2. If a given reaction has a rate of 10 g/s and the temperature is increased by 20 o C, what will the new reaction rate be? 3. What is the name given to the slowest step in a reaction mechanism? 4. Consider the following reaction mechanism: Step 1: CH 4(g) + Cl 2(g) CH 3(g) + HCl (g) (slow) Step 2: CH 3(g) + Cl 2 (g) CH 3 Cl (g) + Cl - (g) (fast) a) Write the equation for the overall reaction. b) Identify the reaction intermediate c) Which step is the rate determining step? Page 9 of 13
5. Consider the following reaction mechanism: Step 1: C 3 H 6 O + H 3 O + C 3 H 7 O + H 2 O (fast) Step 2: C 3 H 7 O + H 2 O C 3 H 5 OH + H 3 O + (slowest) Step 3: C 3 H 5 OH + Br 2 C 3 H 5 OBr + HBr (slow) a) Write the equation for the overall reaction. b) Identify the reaction intermediate(s) c) Identify the catalyst d) Which step is the rate determining step? 6. Explain the difference between an activated complex and an intermediate in terms of their stability. Page 10 of 13
7. When comparing a potential energy diagram for a catalyzed reaction to an uncatalyzed reaction, what value will always decrease and what value will always stay the same? 8. Consider the following reaction where nitrogen monoxide reacts with hydrogen gas to create nitrogen gas and water 2 NO + 2 H 2 N 2 + 2 H 2 O a) The following is the proposed reaction mechanism. Determine Step 2 of the reaction mechanism. Step 1: 2 NO N 2 O 2 (fast) Step 2: (very fast) Step 3: N 2 O + H 2 N 2 + H 2 O (slow) b) Identify the reaction intermediate(s) d) Which step is the rate determining step? Page 11 of 13
Answers: Reaction Rates Hints: 2ai) Mg (s) + 2 HCl (aq) MgCl 2(aq) + H 2(g) 2aii) If a compound is ionic you split it into its ions. If it is not you leave it as is. 2aiii) Remove any ions that are on both sides of the arrow (spectators) 3c) 3d) 3e) 4a) = 4b) 5) The rate is the slope and the slope is rise / run. Reaction Rates Answers: 3. c) 0.195 ml H 2 /s d) 269 ml H 2 e) 128 min 4. a) 32.2 kg Ag b) 0.65g Zn 5. 0.9 g/s Collision Theory and Heat of Reaction Hints: 11) H forward and H reverse will have the same value but opposite signs Page 12 of 13
Collision Theory and Heat of Reaction Answers: 10. a) +35 kj b) -40 kj c) +75 kj d) +40 kj e) 85 kj 11. H forward = -15 kj H reverse = +15 kj 12. 25 kj 13. 40 kj Kinetic Energy and Reaction Mechanisms: 2. 40 g/s Page 13 of 13
Unit 1 Summary Questions /21