This document outlines an experiment to determine how temperature affects the rate of reaction between sodium thiosulfate and hydrochloric acid. It describes the independent variable as the temperature of the hydrochloric acid ranging from 0°C to 80°C. The dependent variable is the time for a cross drawn on paper to become invisible when placed behind a test tube containing the reaction. The method involves timing how long it takes for the cross to disappear at each temperature, with results recorded in a table. The conclusion states that higher temperatures led to faster reaction times, supporting the particle collision theory that increasing temperature causes particles to move faster and collide more frequently.

1. Rate of Reaction
TEMPERATURE

2. Aim:
Aim: To determine how the change in
temperature affects the rate of reaction
between Sodium Thiosulfate and
Hydrochloric acid

3. Variables
• Independent variable (What we are
changing): Temperature of Hydrochloric
Acid (Range: 0*C, 20*C, 40*C, 60*C,
80*C)
• Dependent variable (What we measure to
record for results): Time take in seconds for cross
to visibly disappear (Cross drawn on piece of paper
held behind water bath)

4. Controlled Variables
• Volume of Hydrochloric Acid 2.0 M
• Volume of Sodium Thiosulfate
• Size and position of cross
• Equipment
• Person timing
• Stop watch used to record time

5. Equipment
• Test tubes
• 50mL Beaker
• Hydrochloric Acid 2.0 M
• Sodium Thiosulfate
• Water
• Hot water jug
• Stop watch
• Thermometer
• Paper with cross on it
• Pen

6. Method:
1. Collect all equipment – Test tubes, 50mL
beaker, Hydrochloric Acid, Sodium Thiosulfate,
Stop watch, Thermometer
2. Use hot water jug to boil a beaker full of water
3. Fill test tube with 5mL of 2.0 M Hydrochloric
Acid and place in beaker of water to reach water
temperature
4. Draw a cross on a piece of paper and place on
outside of beaker
5. Measure temperature of Hydrochloric acid, once
it has reached 80*C add 5mL of Sodium
Thiosulfate. At that point start the timer.
6. Watch the cross through the test tube, once it is
not visible stop the timer and record time in
table.

7. 7. Clean test tube out and add 5mL of
Hydrochloric acid to the test tube, place test
tube in beaker.
8. Add some cold water to your hot water beaker
to bring the temperature down to 60*C. Once
the Hydrochloric acid is 60*C add 5mL of
Sodium Thiosulfate.
9. Watch the cross through the test tube, once it is
not visible stop the timer and record time in
table.
10. Repeat steps8,9 and 10 for a second test with
60*C
11. Repeat steps 8,9, 10 and 11 with Hydrochloric
acid at 40*C, 20*C and 0*C

8. Results Table
Time taken for cross to not be visible through test
tube
Temperature
of HCl
Test 1 Test 2 Test 3 Average
80*C
60*C
40*C
20*C
0*C

9. Graph
0
20
40
60
80
100
120
140
160
180
200
0 20 40 60 80 100
East
West
North
How temperature effects rate of reaction between Hydrochloric
acid and Sodium Thiosulfate
Timeinseconds
Temperature in Degrees Celsius

10. Conclusion
• Needs to state what happened in results
and how we know that.
• Talk directly about your results
– What do your results show?
– How did that affect the rate of reaction?
– Justify these findings using data

11. Conclusion
These results show the higher the temperature of the
2.0 Mol Hydrochloric Acid the faster the visibility
of the cross disappeared and therefore the faster
the rate of reaction. The results show this clearly
with the visibility of the cross disappearing in
_____seconds at ____________ for the 2.0 M
Hydrochloric acid compared to the visibility of the
cross disappearing in _______ seconds at
__________ for the 2.0 M Hydrochloric acid.

12. Justification
• Justification: Explanation of why you
did what you did during the method
– What did you keep constant?
– How did you keep that constant?
– How did you ensure your test was fair?

13. Justification
• I used 5 different temperatures of Hydrochloric acid so that
I can have accuracy in my data as the more tests I complete
the more data I have to review
• 1 only had one reaction going at a time to ensure that I
correctly timed the reaction
• I used the same equipment to ensure their were no
differences in the measuring
• I was the only one doing the experiment to keep the
measuring and timing of the experiment the same.
• I accurately measured the volume of Hydrochloric acid and
sodium Thiosulfate so that the volume of acid was not a
factor in the investigation.
• We used a water bath to get the temperature of the acid the
desired temperature.
• I performed the test quickly and efficiently to make sure the
temperature of the acid did not cool down from the
temperature I measured.

14. Discussion
• Relate the finding from your
investigation to the particle collision
theory of reaction:
– As temperature increases what happens to
particles?
– How does this affect the rate of reaction?

15. Discussion
The higher the temperature of Hydrochloric
acid the faster the particles are moving in
the acid. This means the chance of
collision between the two substances is
greater, and therefore the higher the
change of effective collision. The higher
the number of effective collisions between
the Hydrochloric acid and the sodium
Thiosulfate, the faster the reaction will be
completed.

16. AIM:
Aim: To determine how the change in surface area
affects the rate of reaction between calcium
carbonate and Hydrocholoric acid.
Use template to design and record investigation of
the Aim above
You will have:
1. Pestle and mortars
2. Electronic balance to weigh out the calcium
carbonate