• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5

Rate of reaction- Sodium Thiosulphate and Hydrochloric Acid.

Extracts from this document...

Introduction

Rate of reaction- Sodium Thiosulphate and Hydrochloric Acid Introduction When sodium thiosulphate and hydrochloric acid react they produce a cloudy precipitate. The two chemicals are both clear solutions and will react together to form a yellow precipitate of sulphur, the equation for which is as follows: Na2S2O3 + 2HCl ?2NaCl + SO2 + S + H2O As the solution will turn cloudy, we can observe the rate of reaction by placing a black cross underneath the beaker and seeing how long it takes for it to disappear. There are factors that affect this experiment such as temperature, concentration and time. I do not think that surface area will affect the experiment, as both chemicals are liquids. For my experiment I will study concentration as this is easily observed and can be easily varied. Prediction I think that as the concentration of sodium thiosulphate increases, the amount of time taken for a reaction decreases. I know this because before two particles can react they must meet. In a low concentration, the particles will be few and widely spread. This means that the number of reactions will be limited because less particles will meet. At higher concentrations there are more particles and so they probability of them coming into contact with other particles is increased. ...read more.

Middle

This is because if I use above 50 the results will not be affected anyway and so a substantial amount of thiosulphate is not obtainable, due to limitations on the school's resources. This is also the best range to use because in my evaluation I will need to discuss further work, and then I could use 5, 15, 25, 35 and 45 to create further results and make my experiment more accurate. Method Take a piece of paper with an "x" clearly marked on it, conical flask, measuring cylinder and timer. Measure 50cm3 of sodium thiosulphate and 5cm3 of hydrochloric acid. Add the hydrochloric acid to the sodium thiosulphate in the conical flask and gently swirl. Place conical flask on the paper with "x" marked and start the timer. Observe the reaction through the top of the conical flask and stop the timer as soon as the cross can no longer be seen. Repeat experiment with 40cm3 thiosulphate, 5cm3 hydrochloric acid and 10cm3 water. Keep repeating, adding 10cm3 less thiosulphate and 10cm3 more water each time. Record results in a table of results. Apparatus Sodium thiosulphate, hydrochloric acid and water Paper with "x" clearly marked. Conical flask Measuring cylinder Timer Results Time taken for cross to disappear (S) Volume of thiosulphate (cm3) Volume of HCL (cm3) ...read more.

Conclusion

Also, the human eye causes errors such as this The eye could also have made mistakes in judging whether or not the cross had actually completely disappeared If the same person watching the reaction was working the timer, errors could occur in their co-ordination. We could remove these errors by: Making sure the bottom of the meniscus is read so that it is the true reading. Using a burette to measure. This would remove the measuring errors associated with measuring cylinders, as they are correct to 0.1 cm where measuring cylinders are only 0.4. Burettes are a far more accurate way of measuring the correct amounts. Use light sensors to detect when the cross is no longer visible. The experiment could be connected to a light sensor, and to a timer. These light sensors will detect when there is no light shining through the substance. This would automatically stop the timer and therefore make the experiment fairer and more accurate. To further investigate this experiment, I could use a wider range of times. I used 10, 20, 30, 40 and 50 and so I could use the mid points of these times for more accuracy. I could also go up to 100cm3 to obtain more results but this possibly would not affect my experiment. Andy Fraser ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Aqueous Chemistry section.

Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

Related GCSE Aqueous Chemistry essays

1. What factors affect the rate pf reaction between sodium thiosulphate and hydrochloric acid?

I am changing the concentration of sodium thiosulphate because from my preliminary experiments I found that changing the concentration on hydrochloric acid didn't affect the rate of reaction very much. In my preliminary experiment I conducted 3 different experiments. Experiment 1 was to find out which solution affected the rate of reaction the most.

2. The action of amylase and pectinase in varying amounts when clarifying cloudy apple juice.

at that temperature amylase and pectinase work (although it is not their optimum temperature). I decided to use a time of 30 minutes because I thought that would be long enough for some clarification to happen. I set the colorimeter up with distilled water at 0 arbitrary units.

1. The Effect Of Concentration Of The Reaction Between Sodium Thiosulphate And Hydrochloric Acid

The time it takes for the cross to disappear relies on the concentration of the Hydrochloric acid. As the experiment continued, the water to acid ratio was bigger. If there is more water to acid in a solution, it means that there is more water molecules in it.

2. See how long it takes for sodium Thiosulphate and hydrochloric acid to react at ...

I shall do this to make sure the results are as accurate as possible in case one of the experiments we miss calculated and to prevent any bad results. Measurements: In this experiment I am going to measure the time it takes for the cross to disappear from my view.

1. Investigation to find out the lengths of times for a solution of hydrochloric acid ...

These results aren't very accurate so I will have to do the experiment again with a few changes... This time I will get the same equipment and do everything the same, except I will use a wider range of solutions, varying the amount of sodium thiosulphate and water used each time, more than before.

2. Investigate the rate of reaction between colourless solutions, hydrochloric acid and Sodium Thiosulphate by ...

o Pour both reactants in the beaker simultaneously o The concentration of the sodium thiosulphate should also stay constant o Each experiment should also take place at room temperature o Each experiment should be repeated at least three times, to make that the results are accurate.

1. My Aim is to see how concentration of acid will affect the time it ...

.In my pilot I used higher quantities of acid but I discovered that doing this is a waste of time and wasteful because you can make the concentration differ however much acid and water you choose to vary. I used high amount of acids but then discovered the overall solution had the same concentration so I have been less wasteful.

2. To find out how the rate of reaction between sodium thiosulphate and hydrochloric acid ...

This is because by doubling the number of hydrochloric acid molecules present the chance of a collision should be doubled, as there is now twice the possibility of a collision-taking place initially. This can be thought of as like people in an enclosed space, if there is twice the number

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to