Experiment 4 Effect of Temperature on Chemical Kinetics Objective The purpose of this experiment is to determine the activation energy of the reactions between KMnO 4 and H 2 C 2 O 4 under different temperatures by using the Arrhenius Equation Procedure 1 Create 3 water baths each at varying temperatures approximately 10 20 and 30 and an ice bath for about 0 making sure that the difference in temperature of each bath is roughly 10 apart 2 Use a buret to place 20mL of 0 5M H 2 C 2 O 4 in an Erlenmeyer Flask and 10mL of 0 02M KMnO 4 in a 15cm test tube 3 For the 0 put Erlenmeyer Flask into another flask of ice to maintain the temperature For the others put the flask into the water baths 4 Mix the reactants and record the time it takes for the solution to turn yellow brown Swirl the contents regularly as you wait for the reaction to occur 5 Repeat the procedure for your second trial at the temperatures again beside to 0 6 Find the average time of the trials and then determine k for each temperature 7 When complete determine the Activation Energy from the slope after plotting ln k v 1 T Data Collection KMnO 4 mL H 2 C 2 O 4 mL Temp 0 C Reaction Time Trial 1 s Reaction Time Trial 2 s Average Time s 10 20 0 1312 NA 1312 10 20 10 642 604 623 10 20 20 368 390 379 10 20 30 124 116 120 Calculations Determining rate Temp 0 C Rate Calculation Rate KMnO 4 t 0 0 02 1312 1 52E 5 10 0 02 623 3 21E 5 20 0 02 379 5 28E 5 30 0 02 120 1 67E 4 Determining k Temp 0 C k Calculation k Rate KMnO 4 H 2 C 2 O 4 0 1 52E 5 0 02 0 5 00152 10 3 21E 5 0 02 0 5 00321 20 5 28E 5 0 02 0 5 00528 30 1 67E 4 0 02 0 5 0167 Determining EA Temp C Temp K 0 273 10 k Rate Ln k 003663 00152 6 489 9576 92 1151 9 283 003533 00321 5 741 9576 92 1151 9 20 293 003412 00528 5 244 4107 44 494 04 30 303 0033 0167 4 092 10285 7 1237 15 Ea slope R R 8 314 J mol 1 T 1 K Slope From graph EA J mol Discussion Bond energy is the amount of energy required to break a certain chemical bond activation energy is the amount of energy needed for a reaction to occur Therefore if bond energy is high it will require a higher activation energy in order for the reaction to happen In our experiment from the data we can see a trend that as temperature increased activation energy seems to decrease with an exception towards the end that could have been caused by a data collection error Result The purpose of this experiment is to determine the activation energy of the reactions between KMnO 4 and H 2 C 2 O 4 under different temperatures by using the Arrhenius Equation From this we can see there is a negative correlation between temperature increase and activation energy
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