Investigate how I can speed up the rate of reaction between sodium disulphate and hydrochloric acid.

(3) We grounded the marble chips to give more surface area for the particles to attract and react faster.

PREDICTION

I think that the marble will dissolve faster because more acid particles will attack (react.)

I predict that sodium thiosulphate will react quicker with a stronger acid because there are more acid particles.

VARIABLES

Strength of the acid

Volume of sodium thiosulphate

The strength of sodium thiosulphate

Heat the acid

The volume of acid

The volume of water

Stir the mixture

The only thing I will change is the strength of the acid.

I will keep everything else the same to keep it a fair test. The following will remain the same;

Colour/Size of X

Temperature/Heat

Equipment

Equipment List

For this experiment I used the following equipment:

The equipment that I had to use for my investigation to find out how to speed up the rate of reactions between sodium thiosulphate and hydrochloric acid was:

• 3 Beakers
• 2 Measuring Cylinders
• 1 Piece of white paper
• 1 Stopwatch
• 1 conical flask

Procedures

1. I will put 10cms3 hydrochloric acid into a measuring cylinder.
2. I will then put 10cms3 sodium thiosulphate into a measuring cylinder.
3. I will then put hydrochloric acid into a beaker.
4. I will then place it on a white page with a black x.
5. I will add sodium thiosulphate.
6. I will start a stopwatch as soon as it’s added.
7. I will watch how long until the black x disappears.
8. I will then wash the equipment free of any germs.
9. I will then repeat this.
10. I will carry out the following for each experiment

Range of evidence

SAFETY

• Wear safety goggles at all times.
• Wash hands immediately if you spill anything on them
• Report smashed glass immediately to the teacher.

Table of results from experiment

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CONCLUSION

The graph shows that the stronger the acid the quicker the reaction.

The line on the graph goes down showing the time goes down with a stronger acid.

This shows that my prediction is right.  The stronger the acid the quicker the reaction is. This stronger the acid the quicker the reaction is. This is because there are more particles in a stronger acid than a weaker acid, so they have more a chance of reaction with the particles in the sodium thiosulphate.

IMPROVEMENTS

I think I could improve the experiment by using a burette to measure out the acid and water more accurately.