Investigate: To determine the relationship between surface area and rate of oxygen production when potato tissue is placed in Hydrogen peroxide solution

Authors Avatar

Amanda Tam

17/10/01

Chem+Bio coursework

Investigate: To determine the relationship between surface area and rate of oxygen production when potato tissue is placed in Hydrogen peroxide solution

Planning

My prediction

I predict that the bigger surface area of the potato chips, the faster the rate of reaction of the hydrogen peroxide is being use up and the faster the oxygen is being given off.  Also the rate of the oxygen being given off should be directly proportional to each other.

Scientific Theory

Catalyst is one of the factors which affect the speed of a reaction.  Enzyme is one type of catalyst and catalase is an example of enzyme which I will be using in my experiment.  Enzymes works because they cover in active sites which is more specific about molecules they will allow to stick on.  It is often describe as a lock and key mechanism.  In this experiment the lock is the catalse enzyme and the key is hydrogen peroxide.

Diagram to summarize how does the surface areas affect the rate of gas coming off

                                                        

Key:                                            H2O2

Arrows mean H2O2 diffusion

into the potato tissues.

                                                                H2O2

                                                H2O2                        H2O2

                                                                H2O2

The word equation of this experiment is:

                        catalase

Hydrogen peroxide                       Water + Oxygen

                        catalase

2H2O2                                2H2O + O2

Method

  • I will be given a potato and I will cut the potato chips from chip cutter.
  • I will select the best 5 chips from there; I will cut them into same length by using a knife and a ruler.
  • Then I will cut the 5 potato chips into different surface area as shown in analysing.
  • I will fill water in the trough.
  • By using the measuring cylinder, I will measure 100cm3 of the hydrogen peroxide solution.  Then I pour the solution inside the conical flask.
  • I will join the delivery tube to the conical flask.
  • I will set up the burette holding it upright with a clamp stand.
  • I will record the temperature of where the experiment will take place
  • I will record the readings from the burette every 30 seconds for 5 minutes
  • The experiment will be repeated and the potato chips will be cut into thinner pieces each time, in order to see the effect of the surface area on the volume of oxygen
Join now!

Obtaining Evidence

The factor below were all kept constant

  • The temperature were always kept in 21°C.
  • All the chips were from the same potato.

Here are the results that I got

After looking at the results above, I noticed that there had some anomaly in my results by drawing a graph, so I repeated my whole experiment and there are the results I got:

Analysing Evidence

These are the surface area of my and how I cut them:

1st chip which had 1 piece

(5*1*4)+(1*1*2)

=22cm2

                                                

2nd chip which had ...

This is a preview of the whole essay