Lab Report On Iodine Clock

And finally into test tube 3, I pipetted 1.0 ml turnip extract and 4.0 ml of water. The contents of test tube 1 was poured into a spectrometer tube and labeled it “B” for blank. “B” tube was now inserted it into the spectrometer. An adjustment to the control knob was made to zero the absorbance reading on the spectrometer since one cannot continue the experiment if the spectrometer is not zeroed. A combination of two people and a stop watch was now needed to not only record the time of the reaction, but to mix the reagents in a precise and accurate manner. As my partner recorded the time, I quickly poured tube 3 into tube 2. I then poured tube 2 into the experiment spectrometer tube labeled “E” and inserted it into the spectrometer. A partner then recorded the absorbance reading for every 20 seconds for a total of 120 seconds. After the experiment, a brown color in the tube should be observed to indicate the reaction was carried out. Using sterile techniques, any excess liquid left was disposed

3. Turned off the laboratory burner and observed the properties of the product in the evaporating dish.

Procedure: In this experiment, various chemicals were mixed together, to determine a reaction. Using two drops from chemical 1 and two drops of chemical two, unless otherwise stated, then recording the type of physical reaction or color changes that occurred.

The main objective of this experiment is to differentiate between a physical change and a chemical change.

Hypothesis: I believe the rate of reaction will speed up as the temperature increases until it reaches about 37oC, which is the body temperature, where it will begin to slow down and stop reacting. I believe this will occur because enzymes have a temperature range at which they work best in and once the temperature goes out of this range the enzyme will stop working.

The sunlight could affect the speed therefore the experiment will take place in the shade, so that temperature shouldn't change the reaction speed, we will check by using a thermometer. Also the same amount of hydrochloric acid and sodium thiosulphate will be mixed each time so that the concentration changes will affect the same amount of hydrochloric acid and sodium thiosulphate. The concentration of the hydrochloric acid will be changing each time to test if it speeds up a reaction. The speed for the light intensity to drop by 10% will be measured after each attempt so that the affects of concentration changes can be recorded. Each concentration will be tested three times and an average will be worked out, to see if there were any anomalies within the experiment.

Three factors that can affect the rate of reaction are temperature, pH and the salinity.

Question: How does changing enzyme concentration or temperature affect the reaction time of enzyme activity?

Purpose: The purpose of this experiment is to observe a variety of chemical reactions and to identify patterns in the conversion of reactants into products.

The time in the water bath was also controlled to ensure that the enzymes were left to react for the same amount of time, making the experiment

Introduction The purpose of this lab was to test the rate at which the catalyst enzyme reacts and how temperature affects it. Enzymes help to speed up reactions within objects by providing an alternative low energy route for the reaction to occur. In order for a reaction to occur two molecules must collide with each other. The substrate, molecule colliding with the enzyme then locks into it, allowing the enzyme to begin breaking it down.

The heated and cooled compounds were cooled and heated for three minute each. Both compounds had the same temperature for each trial. After when both the heated and cooled compounds were heated and cooled, both compounds were combined into a beaker and was timed to test the reaction time. Of the three temperatures, the heated compounds had the fastest reaction time. The heated reaction had an average reaction time of 6.01 seconds, the room temperature had an average reaction time of 9.49 seconds, and the cooled reaction had a average reaction time of 17.63 seconds.

Another variable tested was decreasing the temperature in the reaction of the enzyme catalase. In these tests, the reaction rate showed a slight decrease because the decreasing of temperature makes molecules move slower, which leads to less of an reaction rate. Tests showed that in one instance when a decreasing of temperature was added, the reaction rate was 9 ml/min. This proves that the decrease of temperature slowed down the reaction rate.

This investigation presents what would occur to the reaction rate of an enzyme if the temperature, pH level, concentration of a substrate and enzyme were changed. In this experiment, the enzyme catecholase, commonly found in plants, was tested and its product formation, benzoquinone was measured. When the concentration of the reactants such as the enzyme catecholase, and the substrate catechol were tested, the results of product formation increased greatly because the higher concentrations allowed the enzymes to increase their activity rates. When physical factors such as temperature and pH were tested the results fluctuated.

The rate at which a reaction occurs, or takes place, is affected by various factors, such as the temperature at which the experiment is conducted in, the pressure which is given, the surface area which is exposed, use of catalysts, and the concentration. In this investigation, I would be investigating the affect of surface area, or particle size, in the rate at which a reaction occurs.