Unit 1 ~ Learning Guide Name:

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1 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! Math in Science (review): Measurements: 1. Why might scientists want to use metric measurements instead of Imperial measurements? What are base units for: Mass: Distance: Try finding this one online: Volume: For specific prefixes, the involve a power of 10 or moving a decimal left or right. Reminder: k h da d c m What does the represent (or what do you put there)? If I give you kg, what is the root unit? If I give you 6.3kg and want to get? g, what would your answer be? Practice: 3.2cm =? mm 3.2cm =? km 40cg =? g 1.3kg =? mg Page 1 of 14

2 Scientific Notation: Based on what you saw and read in this lesson, why might you want to use scientific notation? What is the format of Scientific Notation (include an example): Eg. Convert to Scientific Notation kg kg m m Try math with scientific notation using your calculator: 4.37 x 10 5 x 3.21 x 10 4 = 3.44 x / (6.02 x ) = Significant Figures Rules: What are the 5 rules for significant figures? Page 2 of 14

3 Using the 5 rules, complete the following table. NOTE: If you struggle with any of these, write your question or confusion in the QUESTION column and check in with your teacher for clarification. Eg. # sig figs Rule(s) used Sci Notation Questions? x10-2 Significant Figures: Complete each calculation ending with the correct number of significant figures A chemist cuts a 13.25cm strip of magnesium to use only 5.8cm of it. What length of magnesium remains? A rectangular block has the dimensions 3.2cm x 4.71cm x 12cm. What is the volume of the block? A rectangular garden plot has sides of length 13.21m and 6.10m. What is the area covered by this plot? Dimensional Analysis & Unit Conversions Convert 28.6 seconds to hours? Convert 600min to days Page 3 of 14

4 Convert 7 m/s to km/hr 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 b) Aqueous chlorine is added to a solution of aluminum bromide in a single replacement reaction which forms no precipitate and bromine liquid. 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. Page 4 of 14

5 b) What is the spectator ion for this reaction? c) If 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 5 of 14

6 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 Mass (g) Time (s) What are four factors that affect a reaction rate? Page 6 of 14

7 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 )? 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? Page 7 of 14

8 6. Place the correct numbers for each label in the correct circle. Memorize! PE (kj) 1. Activation Energy Forward 2. Activation Energy Reverse 3. DH Forward 4. DH Reverse 5. Activated Complex 7. The Enthalpy change (DH) for an exothermic reaction will always be (positive/negative)? 8. The Enthalpy change (DH) 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 DH forward? c) What is the value of E A reverse? d) What is the value of DH reverse? Page 8 of 14

9 e) What is the energy of the Activated Complex? f) Will the reactants or products have the strongest bonds? Explain how you know. 11. Use the following information to draw a potential energy diagram. You must first calculate DH forward and DH reverse. Fully label your diagram similar to question 6. E A Forward = + 45 kj E A Reverse = +30 kj Activated Complex Energy = 70 kj PE (kj) 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 9 of 14

10 15. 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 O 2 16 CO H 2 O kj Ba(OH) NH 4 Cl kj BaCl NH 4 OH SOCl 2 + CoCl 2 6H 2 O CoCl 2 + HCl + 6 SO 2 DH = +360 kj Mn (s) + 2 HCl (aq) MnCl 2(aq) + H 2(g) DH = -221 kj Influence of Form of Reaction on Rate 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 10 of 14

11 Kinetic Energy and Reaction Mechanisms: 1. What is the general rule 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 + Cl - (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 11 of 14

12 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. 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) ============================================================== 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 12 of 14

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 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 13 of 14

14 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) Rate = ()*+,-. / 01,- 3d) min x = , > x,?. / =,16 > = 3e) L H B x,? x > x?,?. /,16 > = 4a) min x > x C D6 x,16 >,)* D6 x C D6,)* EC x,)* D6 C EC,)* EC x FC EC C EC = 4b) s x,16 x C EC x >,16,)* EC x C EC,)* D6 x,)* EC C D6 =,)* D6 5) The rate is the slope and the slope is rise / run. Page 14 of 14