The effect of catalase concentration on the breakdown rate of h2o2

The effect of catalase concentration on the breakdown rate of h2o2

The effect of catalase concentrations on the rate of

Break down of hydrogen peroxide

Scientific knowledge and understanding:

A rate is a measure of change that occurs in a given time whilst a

reaction is the interaction of substances undergoing chemical change.

The velocity at which any mix of substances are transformed into a

product/s in a given unit of time is the rate of reaction. The speed

at which this modification occurs relies on two main factors; the

amount of collisions between reacting particles and what portion of

these collisions are successful in producing a change within the

substances present.

Reactions between chemical substances will only occur if the particles

collide with enough energy to break their initial bonds. This initial

energy is called the activation energy.

Collision theory: In order to react, particles must collide with a

force sufficient to overcome the activation energy.

There are four methods of increasing the rate of a reaction, and all

can be explained in terms of increasing the number of collisions

between reacting particles;

1. Temperature: when the temperature is increased particles move

faster as they have more kinetic energy, encouraged by the heat. The

more rapidly particles are moving, the more collisions are going to

occur.

2. Pressure (or concentration): the more concentrated a solution, the

more particles of a reactant are present. The higher the number of

particles present the higher the likelihood of collisions.

3. Surface area: if one of the reactants is a solid then breaking it

up into smaller pieces will increase its surface area. This means that

particles in the solution around it will have a larger area to work

on, so there will be more collisions in a shorter time. If both

reactants are dissolved in solution/in a liquid state, surface area

does not pertain and they relate directly to pressure/concentration.

4. Catalysts: catalysts work by giving the reacting particles a

surface to stick to, where they can bump into each other. A catalyst

can also lower the activation energy of particles. This will obviously

increase the number of successful collisions.

An enzyme is a protein that acts as a biological catalyst, speeding up

the rate at which a biochemical reaction takes place, w...

... middle of paper ...

... decided to carry on each experiment for 3 ½ minutes to end up with

14 results for each concentration. The more results are obtained the

easier it is to plot a graph and draw in the line of beat fit. I

shortened the time to 3 ½ minutes from 5, which I did in my

preliminary because the volume did not alter very much after 4 minutes

and this way I would be able to carry out the same experiment more

times, to give me a more accurate average result.

Safety:

Of the apparatus being used some is made of glass, and therefore very

fragile. Care must be taken to ensure that none of the apparatus is

knocked over/falls and breaks, as the glass would shatter.

In the event of any breakages, DO NOT TOUCH ANY BROKEN GLASS, but call

the supervising teacher immediately.

Hydrogen peroxide must also be handled with caution. It is a corrosive

chemical; so a lab coat and goggles must be worn. If contact is made

with the skin, wash immediately with soap and water. To reduce the

risk of any spillages, the transfer of H2O2 to different vessels

should be limited, such as in step 5 of the method where it is

transferred from the beaker to the syringe straight to the conical

flask.