This document describes an experiment to observe the effect of temperature changes on reaction rate. The experiment involves a reaction between potassium permanganate, sulfuric acid, and oxalic acid. The reaction rate is determined by measuring the time it takes for the purple permanganate solution to become colorless. Results show that as temperature increases from 40°C to 70°C, the reaction time decreases and the reaction rate increases. The conclusion is that higher temperatures lead to faster reaction rates.

1. THE EFFECT OF TEMPERATURE CHANGES ON REACTION RATE Alberto Cánovas and Estefanía Jiménez.

2. ITRODUCTION The aims of this experiment... Initially the reaction mixture is purple in colour due to the presence of permanganate ions but it will turn colourless as soon as they are used up. This colour change allows us to follow the course of the reaction. If the amount of the permanganate ions iniatially present in a series of experiments is the same, then the point at which the purple colour disappears will always represent the same extent of reaction. So if it is the time it take for the colour change to occur then take 1/t as a measure of the reaction rate.

3. REQUIREMENTS -DISTILLED WATER -SELECTION OF SYRINGES -BEAKERS -THERMOMETER -ELERMEYER FLASK -HEATER HAZARDS! -OXALIC ACID -SULPHURIC ACID -POTASSIUM PERMANGANATE

4. Days before, we prepared the dissolutions!!

5. The process is similar always, the only thing that changes is the teperature and therefore the reaction rate.

6. PROCEDURE 1. Using syringes add 5 cm3 of sulphuric acid, 2cm3 of potassium permanganate solution and 40 cm3 of water to a 100 cm3 dry glass beaker. 2. Heat the mixture to about 40ºC,later 50ºC,60ºC and 70ºC.

7. 4. Add the oxalic acid to the mixture in the beaker as soon as possible and at the same time start the timer. 3. Place the beaker on a white.

8. 5. Gently stir the reaction mixture with the thermometer. 6. When the reaction mixture just turn colourless stop the timer ans record the time. Measure and record the temperature of the reaction mixture.

10. RESULTS   Time (sec) Temperature (ºC) Reaction rate 126 40ºC 0.0079 66 50ºC 0.015 46 60ºC 0.022 15 70ºC 0.066

11. CONCLUSIONS When we increase the temperature, the reaction rate is very fast, but when we decrease the temperature, the reaction rate is very slow. This lab activity has been a great experience for us!!   