Increasing concentration-there are more particles in the same amount of space so they are more likely to collide
Adding a catalyst- the catalyst makes the particles react more easily and quicker
Increasing Surface area- Allows the particles more space where they can collide with each their.
By doing any of these in a reaction, increases the chances of the reactants’ particles colliding with each other.
Investigation Method
Here is the first Method I will use to obtain my results in a trial experiment.
- Use a large measuring cylinder to measure out 40ml of Sodium Thiosulphate into a clean conical flask.
- Put the conical flask over a piece of paper with a cross printed on it.
- Record temperature of Sodium Thiosulphate.
- Measure 2ml of Hydrochloric acid using a burette into a test tube.
- Get a stop clock. Add the acid to the solution and time how long the cross stays visible for. Record next to temperature
- Thoroughly cleanse the conical flask and measure another 40ml of Sodium Thiosulphate.
- Gently heat the Sodium Thiosulphate until it is 5C° hotter.
- Repeat experiment until five different temperature readings have been recorded.
I predict that the rate of reaction will increase as the temperature increase. The reason I think this is because as the particles have more energy they are more likely to collide and will collide at a greater speed.
Equipment Needed: Burette
Conical Flask
Measuring cylinder
Bunsen burner
Tripod
Gauze
Heat proof matt
Stop watch
Safety
For safety reasons dilute hydrochloric acid should be used and safety goggles should be worn.
Also whilst heating the Sodium Thiosulphate, any long hair should be tied back.
Fair test
I will ensure my results will be fair by:
- Making sure the sodium Thiosulphate is exactly the temperature it is supposed to be.
- Also I will make sure the temperature of the Hydrochloric acid is always at room temperature
- I will clean out all apparatus thoroughly so there cannot be a reaction with more than 40ml Sodium Thiosulphate and 2ml Hydrochloric acid.
- I will start the stop watch when all of the hydrochloric acid has entered the solution. And I will stop the timer when the whole of the cross is invisible.
Diagram
I will measure the time in seconds and the temperature in C°
Trial Experiment
After doing a small trial experiment I noticed that using 2ml of Hydrochloric acid took a long time to react. There fore I decided to increase the amount used to 3ml.
RESULTS
I will be using the average of the 3 sets of results in my graph.