Chapter 12: Chemical Kinetics Kinetics and Graphs

Kinetics Summary Worksheet 1. C decomposes to form D. The following results were obtained by experiment. Time (s) Volume of Gas (mL) 5 18 10 34 15 47 20 57 25 63 30 67 35 69 40 70 45 80 70 60 50 40 30 20 10 5 10 15 20 25 30 35 40 45 Time (s)

Kinetics Summary Worksheet 1. C decomposes to form D. The following results were obtained by experiment. (b) When is the reaction fastest? How can the graph be used to tell? At the beginning of the reaction. The curve has the steepest gradient at this point Time (s) Volume of Gas (mL) 5 18 10 34 15 47 20 57 25 63 30 67 35 69 40 70 45 80 70 60 50 40 30 20 10 5 10 15 20 25 30 35 40 45 Time (s)

Kinetics Summary Worksheet 1. C decomposes to form D. The following results were obtained by experiment. (c) How long does it take for the 0.07g of magnesium to react? Read from the graph the point at which the curve becomes horizontal Time (s) Volume of Gas (mL) 5 18 10 34 15 47 20 57 25 63 30 67 35 69 40 70 45 80 70 60 50 40 30 20 10 5 10 15 20 25 30 35 40 45 Time (s)

Kinetics Summary Worksheet 1. C decomposes to form D. The following results were obtained by experiment. (d) Sketch another curve on to your graph that might have been obtained if 0.07g of magnesium powder had been used instead of magnesium ribbon. Same start and finish but steeper at the beginning. Curve for powder should reach a horizontal earlier than the curve with ribbon Time (s) Volume of Gas (mL) 5 18 10 34 15 47 20 57 25 63 30 67 35 69 40 70 45 80 70 60 50 40 30 20 10 5 10 15 20 25 30 35 40 45 Time (s)

Kinetics Summary Worksheet 1. C decomposes to form D. The following results were obtained by experiment. (e) Suggest two other factors that would alter the rate of this reaction. Change of temperature, addition of a catalyst Time (s) Volume of Gas (mL) 5 18 10 34 15 47 20 57 25 63 30 67 35 69 40 70 45 80 70 60 50 40 30 20 10 5 10 15 20 25 30 35 40 45 Time (s)

Kinetics Summary Worksheet 1. C decomposes to form D. The following results were obtained by experiment. (f) Write a chemical reaction for this process. Mg(s) + 2HNO3(aq) ® Mg(NO3)2(aq) + H2(g) Time (s) Volume of Gas (mL) 5 18 10 34 15 47 20 57 25 63 30 67 35 69 40 70 45 80 70 60 50 40 30 20 10 5 10 15 20 25 30 35 40 45 Time (s)

Kinetics Summary Worksheet 2. The table below shows how the volume of carbon dioxide collected varied against time when small and large calcium carbonate chips were added to an excess of hydrochloric acid. 20 40 60 80 100 120 140 160 180 15 30 45 75 90 105 135 150 165 195 Time (s)

Kinetics Summary Worksheet 2. The table below shows how the volume of carbon dioxide collected varied against time when small and large calcium carbonate chips were added to an excess of hydrochloric acid. (b) What can you deduce about the total mass of the chips relative to one another in each of the experiments? They were the same 20 40 60 80 100 120 140 160 180 15 30 45 75 90 105 135 150 165 195 Time (s)

Kinetics Summary Worksheet 2. The table below shows how the volume of carbon dioxide collected varied against time when small and large calcium carbonate chips were added to an excess of hydrochloric acid. (c) How long did each experiment take to go to completion? How can you tell from the graph? Read from the graph the point at which the curves become horizontal 20 40 60 80 100 120 140 160 180 15 30 45 75 90 105 135 150 165 195 Time (s)

Kinetics Summary Worksheet 2. The table below shows how the volume of carbon dioxide collected varied against time when small and large calcium carbonate chips were added to an excess of hydrochloric acid. (d) What are possible units of rate of reaction in this experiment? mL per unit time 20 40 60 80 100 120 140 160 180 15 30 45 75 90 105 135 150 165 195 Time (s)

Kinetics Summary Worksheet 2. The table below shows how the volume of carbon dioxide collected varied against time when small and large calcium carbonate chips were added to an excess of hydrochloric acid. (e) Write a chemical reaction for this process. CaCO3(s) + 2HCl(aq) ® CaCl2(aq) + CO2(g) + H2O(l) (f) Why is gas produced at different rates in the two different experiments? Size of chips dictates surface area. The smaller the chips, the greater the surface area and the faster the rate of reaction

Kinetics Summary Worksheet 3. Kinetic results for a reaction involving substance A are shown below. (b) What is the order of this reaction with respect to A? First Order Time (min) [A] in mol L-1 0.000 1.00 2.00 0.82 4.00 0.67 7.00 0.49 10.0 0.37 14.0 0.24 20.0 0.14 25.0 0.08

Kinetics Summary Worksheet 3. Kinetic results for a reaction involving substance A are shown below. (c) Use your graph to calculate the half-life for this reaction. Approximately 7 minutes. Time (min) [A] in mol L-1 0.000 1.00 2.00 0.82 4.00 0.67 7.00 0.49 10.0 0.37 14.0 0.24 20.0 0.14 25.0 0.08

Kinetics Summary Worksheet 3. Kinetic results for a reaction involving substance A are shown below. (d) Given that in this reaction A reacts with G, and that the order with respect to G is second, write the rate equation for this reaction. Rate = k [A][G]2 Time (min) [A] in mol L-1 0.000 1.00 2.00 0.82 4.00 0.67 7.00 0.49 10.0 0.37 14.0 0.24 20.0 0.14 25.0 0.08

Kinetics Summary Worksheet 4. (b) What is the order with respect to B in this reaction? Zero (c) What can be said about the rate of consumption of B in this reaction? It is constant. Time in minutes [B] in mol L-1 0.00 1.00 2.00 0.790 4.00 0.590 7.00 0.300 10.0 0.000 0.2 0.4 0.6 0.8 1 1.2 2 4 6 8 10 12 Time (min)

Kinetics Summary Worksheet 5. (b) What is the order with respect to X in this reaction? Zero [X] in mol L-1 0.0032 0.0064 0.0096 0.0100 0.0111 0.0200 Rate in moles per minute 9.2

Chapter 12: Chemical Kinetics Kinetics and Graphs