catalyst on-the-rate-of-reaction-teacher’s-guide

EFFECT OF CATALYST ON THE RATE OF REACTION

Teacher’s Guide/ Chemistry Form 5/ Spreadsheet

SCIENTIFIC CONCEPT

Rate of reaction is the speed at which reactants are converted into the products in a chemical

reaction. For the reaction that occurs rapidly, the rate of reaction is high. Conversely, for a

reaction that occurs slowly, the rate of reaction is low. The time taken for a fast reaction is

short, whereas the time taken for a slow reaction is long. Hence, the rate of particular reaction

is inversely proportional to the time taken for the reaction. One of the factors that can be

affecting the rate of reaction is catalyst. A catalyst is a substance which can alter the rate of a

chemical reaction while itself remains chemically unchanged at the end of the reaction. The

effect of the amount of catalyst on the rate of reaction can be determine by comparing two

experiment. The first experiment is the rate of reaction by using 0.2g of manganese (IV) oxide

powder. While, the second experiment is rate of reaction by using 0.8g of manganese (IV)

oxide powder. When the amount of a catalyst used increases, the rate of reaction also

increases.

Experiment 1: The rate of reaction by using 0.2g of manganese (IV) oxide powder.

Time (s) 0 30 60 90 120 150 180 210 240

Burette

reading (cm3)

48.60 42.00 36.10 30.70 25.60 21.20 16.80 13.40 9.95

Volume of

oxygen gas

liberated (cm3)

0.00 6.60 12.50 17.90 23.00 27.40 31.80 35.20 38.65


Time (s) 0 30 60 90 120 150 180 210 240

Burette

reading (cm3)

49.30 40.55 34.30 28.30 23.10 18.35 14.20 10.30 6.90

Volume of

oxygen gas

liberated (cm3)

0.00 8.75 15.00 21.00 26.20 30.95 35.10 39.00 42.40

UNIQUE FEATURE OF THIS ACTIVITY

The data can be manipulated easily, for example every 30 second, the level of water in

the burette was taken.

Data displayed in a systematic manner, save time in drawing graph, show relationship

of the volume of oxygen gas liberated against time for both experiment on the same

axes.

Student will discover that a spreadsheet can be used to process data.

Allow the student to do more important things such as analyzing the data or the graph.

ENGAGE

You are given two different pictures. Observe the picture carefully.

( A) ( B )

What can you observe from the picture?

Based on the picture, which one is moving faster?

EMPOWER

Step

1. Student are given:

50 cm³ measuring cylinder

150 cm³ conical flask

Stopper with delivery tube

Burette

Retort stand and clamp

Basin

Electronic balance

Stopwatch

Spatula

Beaker

2-volume hydrogen peroxide solution

Manganese (IV) oxide powder

2. Student needs to plan an experiment to determine the effect of catalyst on the

rate of reaction.

3. Student has to construct a hypothesis for this experiment.

4. Student should know the effect of catalyst of the reaction.

5. Help student to determine the variables involved.

6. You may give these instructions to start the activity:

Open a spreadsheet file

Name the file as ‘the effect of catalyst on the rate of reaction’

Fill a burette with water until it is full. Invert the burette over water in a

basin and clamped vertically using a retort stand.

Adjust the water level in the burette and record the initial reading of

burette.

By using a measuring cylinder, measure 50 cm³ 0f 2 volume hydrogen

peroxide solution and pour it into a conical flask.

Weight 0.2g of manganese (IV) oxide powder by using an electronic

balance and poured carefully into a conical flask.

Close the conical flask immediately with stopper fit with a delivery tube

direct to the burette. At the same time, immediately start the stopwatch.

Shake the conical flask with its content slowly and record the volume of

oxygen gas collected in the burette at regular intervals of 30 seconds for

4 minutes.

Repeat the procedure by using 0.8g manganese (IV) oxide powder.

How to set up the spreadsheet

1. Insert the data that obtain from the experiment to the table

2. Insert the border in the table.

How to draw a graph with the spreadsheet

1. Select a line graph

2. Highlight B4 to K4, click ‘Series’, this will draw a line graph base the data from the highlight area that is concentration versus time taken.

3. Click ‘category(x) axis’ label, highlight C4 to K4 (this will show the actual scale of x-axis according to the data), then click ‘Next’.

4. Name the chart

5. Label the x-axis and y-axis as time and volume of gas oxygen liberated.

6. Apply the same step to draw the second graph, volume of gas oxygen liberated

versus time.

RESULTS:


Time (s) 0 30 60 90 120 150 180 210 240

Burette

reading (cm3)

48.60 42.00 36.10 30.70 25.60 21.20 16.80 13.40 9.95

Volume of

oxygen gas

liberated (cm3)

0.00 6.60 12.50 17.90 23.00 27.40 31.80 35.20 38.65


Time (s) 0 30 60 90 120 150 180 210 240

Burette

reading (cm3)

49.30 40.55 34.30 28.30 23.10 18.35 14.20 10.30 6.90

Volume of

oxygen gas

liberated (cm3)

0.00 8.75 15.00 21.00 26.20 30.95 35.10 39.00 42.40

graph of volume of oxygen gas liberated against time

0

5

1015

20

25

3035

40

45

0 100 200 300

time (s)

vo

lum

e o

f o

xy

ge

n g

as

lib

era

ted

(c

m3

)

0.2g manganese (IV)oxide

0.8g manganese (IV)oxide

QUESTION:

1. Which the reactant that having the highest the rate of reaction?

2. What type of catalyst that we use in this experiment? Why?

3. What type of gas formed in the burette?

ANSWER:

1. 0.8g manganese (IV) oxide powder.

2. Positive catalyst because the catalyst increases the rate of reaction.

3. Oxygen gas

ENHANCE

A= wash with small B= wash with large

amount of detergent amount of detergent

When both plates are washed, which one is faster to clean? Explain.

ANSWER:

Plate B will clean first. It is because detergent like a catalyst will clean the plate easily

due to the large amount of detergent that used. The larger amount of detergent used

will increase the rate of reaction between oil and detergent.

catalyst on-the-rate-of-reaction-teacher’s-guide

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