NAME: Serina Alashi
TITLE: Decomposition reaction: hydrogen peroxide (H2O2) decomposed into hydrogen and oxygen ( H2 and O2)
QUESTION: How will changing the concentration of hydrogen peroxide affect the rate of reaction, that is represented by the increase in pressure over time?
Introduction: Hydrogen peroxide is a chemical compound of hydrogen and oxygen. It is a very strong oxidant but weak in water solution. Hydrogen peroxide decomposes into water and oxygen when heated above about 80°C and also decomposes in the presence of a catalyst. A catalyst is a substance that increases the rate of a chemical reaction but is not changed by the reaction. The catalyst in this case would be breaking hydrogen …show more content…
Triplicate trials were performed on each concentration to obtain the mean.
Rate of reaction of hydrogen peroxide decomposition r=(Δpressure/time)/kPa* s-1 Rate of reaction is represented by the peroxide decomposition change of pressure over time. Pressure was measured by using the gas pressure sensor. The same sensor was used throughout the experiment. Also the shortest tube was used to reduce systematic errors.
Controlled Recording initial rate Amount of enzyme Temperature Volume of hydrogen peroxide solution Size and type of test tubes Hydrogen peroxide Cap the test tube immediately with the gas pressure sensor once the hydrogen peroxide is poured inside to be able to record the most accurate data.
Be very carful when adding drops of enzyme because even the slightest drop can affect it completely. To have the most accurate measurements use micropipette and use 10 micro-liters of enzyme.
Be sure to keep the room temperature at a constant rate of about 25C due to the fact that the rate of reactions is related directly to the …show more content…
Set time to 300 seconds.
Step 4: Immediately cap the graduated cylinder with the gas pressure sensor to record initial rate
Step 5: After the initial rate has been calculated, add 10 micro-liters of catalyst using a micropipette into the hydrogen peroxide
Step 6: Measure the pressure build up of the catalyst with the hydrogen peroxide, again using the gas pressure sensor
Step 7: Constantly stir the hydrogen peroxide with the magnetic stirrer to release oxygen gas trapped inside the solution
Step 8: Add 10, 20, 30, and 40 ml of distilled water into the test tubes
Step 9: Draw 1 mL of solution from the graduated cylinder with a micropipette and transfer it to test tube B and mix thoroughly. (The solution that originally had a volume of 10 ml now has a volume of 1 mL in test tube B. The solution, therefore, has been diluted by a factor of 10.)
Step 10: Move 1 mL of the solution from test tube B to test tube C using the technique described previously and thoroughly mix the contents of test tube C. (The solution in test tube C has been diluted by a factor of 100.)
Step 11: Repeat the same techniques from step 9 and 10 but by performing it for the other test